硫酸分析
工业硫酸含量的测定分析
工业硫酸含量的测定分析工业硫酸的含量测定是工业化学分析中常见的一项分析技术。
硫酸是工业生产中广泛使用的一种重要化学品,其含量的准确测定对于生产工艺的控制以及质量的保证至关重要。
本文将介绍工业硫酸含量测定的原理、方法和应用。
一、工业硫酸含量测定的原理酸碱滴定法是通过将标定的酸溶液滴定到含有硫酸的溶液中,利用反应的化学方程式得到硫酸与酸溶液之间的化学反应,进而计算出硫酸的含量。
二、工业硫酸含量测定的方法1.酸碱滴定法步骤如下:(1)将定量的硫酸溶液倒入滴定烧杯中。
(2)配制氢氧化钠或氧化钠溶液。
(3)用滴管将氢氧化钠溶液滴定到硫酸溶液中,直到溶液中的颜色出现明显的变化。
(4)记录滴定的滴数。
(5)根据酸碱滴定反应的化学方程式,计算出硫酸的含量。
2.重量法步骤如下:(1)取一定重量的硫酸样品。
(2)将样品溶解于一定体积的水中,制备一定浓度的硫酸溶液。
(3)将溶液进行物质的加热和蒸发,直至溶液中只剩下硫酸。
(4)将残留的硫酸定量称重。
(5)根据样品的质量和硫酸的质量,计算出硫酸的含量。
3.光度法该方法是利用硫酸与有机染料之间的物质反应。
在一定条件下,将硫酸样品与染料反应后,根据反应物质的吸光度测定硫酸的含量。
三、工业硫酸含量测定的应用1.质量控制:对于生产过程中的硫酸含量进行准确测定可以帮助企业监控生产工艺,确保产品的质量。
2.质量评估:对于供应商提供的硫酸样品进行含量测定,可以评估其产品质量的稳定性和可靠性。
3.质量检测:在产品出厂前,对最终产品中的硫酸含量进行测定,以确保产品满足相关的质量标准和要求。
4.工艺改进:通过对硫酸含量的测定,可以评估和改进生产工艺,提高产品的质量和性能。
综上所述,工业硫酸含量的准确测定对于生产过程的控制、质量的保证以及工艺的改进具有重要意义。
酸碱滴定法、重量法和光度法是常用于工业硫酸含量测定的方法。
这些方法不仅可以满足工业生产的需求,还可以为企业提供准确、可靠的数据支持,从而提高产品质量和市场竞争力。
硫酸的工业制法分析解析
6.什么是热交换过程? 6. 什么是热交换过程?
通过热交换器把反应时生 成的热,传递给进入接触 室的需要预热的混合气体, 并冷却反应后生成的气体, 像这样传递热量的过程就 是化学工业上常用的热交 换过程。
返回
7.吸收SO3为什么不直接用水或 稀硫酸,而是用98.3%的浓硫酸?
因为用水或稀硫酸作吸收 剂时,容易形成酸雾,吸 收速度慢且吸收不充分, 而 用 98.3% 的 浓 硫 酸 作 吸 收剂,则在吸收过程中不 形成酸雾,吸收速度快且 吸收充分,有利于SO3的吸 收。
关于多步反应变一步的计算
步骤: 1.写出多步反应的化学方程式; 2.找出主要原料和最终产物之间的物质的 量的对应关系。即找出主要原料和最终产 物中所含关键原子个数关系。 3.列出关系式,解出答案。
守恒原则
•计算中可以按照守恒、累积、转化的三原则处 理有关过程及数据以化难为易。 •1.守恒原则:如黄铁矿制硫酸中 S 原子守恒,具 体表现形式为 •FeS2——2H2SO4 或 S——H2SO4
返回
2.为什么把燃烧黄铁矿的炉子叫沸腾 炉?为什么用这种炉子?
这是因为矿粒燃烧的时候, 从炉底通入强大的空气流, 把矿粒吹得在炉内一定空 间里剧烈沸腾,好象“沸 腾着的液体”一样。因此, 人们把这种炉子叫沸腾炉。 矿粒在这种沸腾情况下, 跟空气充分接触,燃烧快, 反应完全,提高了原料的 利用率。
返回
三.有关化学计算
•几个概念:化学计算中涉及到工业生产实际中 的“四率”(即转化率、利用率、产率、损失 率)和纯度。 •物质的纯度=(纯物质/不纯物质)×100% •产率=(实际产量/理论产量)×100% •利用率=(实际利用原料量/实际投入原料总量) ×100% •损失率:1-利用率 •在原料中:转化率=利用率
硫酸燃烧的原因分析和相关建议
硫酸燃烧的原因分析
及相关措施建议
一引起硫酸燃烧的原因:
1. 硫酸本身不燃烧。
无论燃烧或爆炸都是硫酸产生其他物质引起燃
烧或爆炸。
浓硫酸遇水会大量放热,严重时会发生爆炸,因此一般情
况下稀释浓硫酸时都是要将酸缓慢加入水中,并不断缓慢搅动,任何
情况下不能往浓硫酸中快速大量加水,
2. 稀硫酸遇活泼金属铁会放出可燃可爆气体氢气。
氢气的爆炸极限
是4.0%~75.6%(体积浓度),意思是如果氢气在空气中的体积浓度
在4.0%~75.6%之间时,遇火源就会爆炸,而当氢气浓度小于 4.0
%或大于75.6%时,即使遇到火源,也不会爆炸。
反应方程式
(1)铁与稀硫酸反应:Fe+H2SO4=FeSO4+H2(气)
(2)氢气与氧气遇明火反应 2 H2+O2=(明火)2 H2O 发生爆炸
二相关建议:
1. 加强管理,严禁明火,杜绝爆炸源。
杜绝一切明火操作行为。
(还
需要特别注意设备电器接触产生火花、气割气焊等明火操作、禁止吸
烟。
)
2 加强通风,降低氢气浓度。
远离氢气的爆炸极限。
(可考虑吸风及
排风装置)
3 配备专用的灭火装置,严禁用水扑火。
(硫酸遇水会大量放热,严
重时会发生爆炸)
4 加强安全巡检,发现异常情况,立即予以处理,消除安全隐患。
PDF 文件使用 "pdfFactory Pro" 试用版本创建。
(AR)分析纯
硫酸(AR)分析纯产品介绍有害物成分浓度CAS NO.硫酸95-98% 7664-93-9管制信息硫酸(*)(腐蚀)(易制毒-3)(易制爆)该品根据《危险化学品安全管理条例》、《易制毒化学品管理条例》受公安部门管制。
[1]CAS号7664-93-9[1]性状:无色无味澄清油状液体。
成分/组成:浓硫酸98.0%(浓)<70%(稀)密度:98%的浓硫酸1.84g/mL摩尔质量:98g/mol物质的量浓度:98%的浓硫酸18.4mol/L相对密度:1.84。
沸点:338℃溶解性:与水和乙醇混溶凝固点:无水酸在10℃,98%硫酸在3℃时凝固。
中心原子杂化方式:sp3[2] 2.溶解放热浓硫酸溶解时放出大量的热,因此浓硫酸稀释时应该“酸入水,沿器壁,慢慢倒,不断搅。
”若将水倒入浓硫酸中,温度将达到173℃,导致酸液飞溅,造成安全隐患。
硫酸是一种无色黏稠油状液体,是一种高沸点难挥发的强酸,易溶于水,能以任意比与水混溶。
[2] 3.共沸混合物熔点:10℃沸点:290℃(100%酸),沸点:338℃(98.3%酸)但是100%的硫酸并不是最稳定的,沸腾时会分解一部分,变为98.3%的浓硫酸,成为338℃(硫酸水溶液的)共沸混合物。
加热浓缩硫酸也只能最高达到98.3%的浓度。
硝酸(AR)分析纯产品介绍有害物成分浓度CAS NO.硝酸65%-68% 7697-37-2管制信息硝酸(*)(腐蚀)(易制爆)本品根据《危险化学品安全管理条例》受公安部门管制。
中文名称:硝酸别名:硝镪水,镪水,氨氮水浓度为68%以下称为稀硝酸浓度为68%~98%称为浓硝酸浓度为98%以上称为发烟硝酸无色透明液体。
有窒息性刺激气味。
含量为68%左右,易挥发。
在空气中产生白雾,是硝酸蒸汽于水蒸汽结合而形成的硝酸小液滴。
露光能产生四氧化二氮而变成棕色。
有强酸性。
能使羊毛织物和动物组织变成嫩黄色。
能与乙醇、松节油、碳和其他有机物猛烈反应。
能与水混溶。
硫酸的安全分析方法
硫酸的安全分析方法硫酸是一种广泛应用于化工、实验室等领域的化学品,具有很高的腐蚀性和危险性。
为了确保操作人员和环境的安全,进行硫酸的安全分析至关重要。
本文将介绍几种常用的硫酸安全分析方法,并提供相应的操作建议和注意事项。
一、物理性质分析法物理性质分析是通过测量硫酸的密度、溶解度、沸点等参数来进行安全评估的一种方法。
1. 密度测定:硫酸的密度与其浓度密切相关,一般情况下,浓度越高,密度越大。
可通过使用密度计或者比重瓶的测量方法,准确地测定硫酸的密度,并与相关的数据表进行比对,以判断硫酸的浓度是否符合要求。
2. 溶解度测试:硫酸的溶解度与温度和浓度密切相关。
通过将一定量的硫酸加入一溶剂中,加热并搅拌,观察其是否能充分溶解。
存在溶解度限制的情况下,应根据相关资料确保在操作时不会超过溶解度限制,以防溶液的超饱和和结晶。
3. 沸点测定:硫酸的沸点为约337摄氏度,可以通过沸点计或蒸馏方法进行测定。
沸点测定可以判断硫酸的纯度,纯度越高,沸点与标准沸点越接近。
二、化学性质分析法化学性质分析是通过检测硫酸与其他物质的反应性,来评估其安全性的一种方法。
1. 酸碱性测试:可通过pH试纸或酸碱指示剂对硫酸进行测试,观察其酸碱性质。
硫酸为强酸,其pH值通常在0-1之间,表明其高度酸性。
2. 金属腐蚀性测试:硫酸具有很强的腐蚀性,可对不同金属进行测试,观察其与硫酸接触后的反应情况。
如产生气泡、溶解或生成沉淀等现象表明该金属与硫酸有反应,应注意避免它们的接触。
3. 可燃性测试:硫酸为非可燃性物质,但与易燃物质接触时可能引发火灾。
可进行试验观察其与易燃物质的反应,若有反应则需采取相应的措施避免火灾发生。
三、安全操作建议和注意事项1. 对于硫酸的密度、溶解度和沸点测试,操作人员应佩戴防护手套、护目镜等个人防护装备,避免直接接触硫酸。
2. 在进行硫酸的化学性质测试时,应使用相应的试剂和实验器材,严格按照操作规程进行,避免硫酸与其他物质接触造成意外发生。
浓硫酸的成分介绍大概
一、废硫酸中各成分分析硫酸(HSO;)纯品是无色油状液体,工业品如果含有杂质,则呈黄、棕等色。
纯度为98.3%2的硫酸,相对密度为1.834,熔点10.49℃,沸点338℃。
将纯度为100%的硫酸加热至290℃,其将分解放出三氧化硫。
硫酸无臭,但发烟硫酸有强烈的刺激性。
它是一种活泼的二元强酸,能与许多金属或金属氧化物作用而生成硫酸盐。
浓硫酸有强烈的吸水作用和氧化作用,可吸收大气中的水分,也可使有机物失水碳化。
硫酸是重要的基本化工原料,用途十分广泛,如制造硫酸钱、过磷酸钙、硫酸铝、二氧化钦、合成药物、合成染料及合成洗涤剂等。
硫酸在有机合成中被用作脱水剂和磺化剂,在金属、搪瓷等工业中被用作酸洗剂,在石油工业中被用于精炼石油制品等。
生产硫酸的原料有硫铁矿、硫黄及有色金属冶炼气等。
硫酸生产方法有铅室法、塔式法和接触法等,目前广泛采用的是接触法,其主要过程包括二氧化硫的制备、净化、转化和三氧化硫的吸收4个部分。
1、硫酸中氯离子的测定:氯离子选择电极2、氯气的测定:碘量法滴定3、硫酸的起始浓度测定:国标中的方法(如下):5. 1 硫酸的测定方法提要以甲基红,一次甲基蓝为指示剂,用氢氧化钠标准滴定溶液中和滴定以测得硫酸含量试剂和材料氢氧化钠标准滴定溶液:c(NaOH)=0.5 m ol/L,甲基红一次甲基蓝混合指示剂。
分析步骤试料溶液的制备浓硫酸(总酸度)用已称量的带磨口盖的小称量瓶,称取约0.7 g 试样(精确至0.0001 g ),小心移人盛有50ml水的250 ml一锥形瓶中,冷却至室温,备用。
滴定于试液中加2-3滴混合指示剂,用氢氧化钠标准滴定溶液滴定至溶液呈灰绿色为终点。
分析结果的表述浓硫酸工业硫酸中硫酸的质量分数*(%)按式(1)计算:蒸馏后产品成分及其浓度的分析:目前已滴定法作为主。
硫酸火灾事故分析
硫酸火灾事故分析引言火灾是一种常见的事故,发生火灾会给人们的生命财产造成严重的损失。
硫酸是一种极具腐蚀性的化学品,一旦发生火灾,可能会造成更严重的后果。
因此,对硫酸火灾事故进行深入的分析和研究,对于预防和控制火灾具有重要的意义。
一、硫酸的性质和危害硫酸,分子式为H2SO4,是一种无色透明的油状液体,是化学工业中常用的一种强酸。
硫酸具有强烈的腐蚀性,对人体、皮肤、眼睛等造成严重的损害,同时也对环境造成污染。
当硫酸遇到可燃物质时,会引发火灾甚至爆炸。
二、硫酸火灾事故的发生原因1. 设备故障硫酸生产过程中,使用的设备可能由于老化、磨损或不当操作等原因导致故障,从而引发火灾事故。
2. 人为操作失误在硫酸生产和储运过程中,人为操作失误可能会导致硫酸泄漏或者接触可燃物质,从而引发火灾。
3. 供电系统故障供电系统故障可能导致生产设备停电,从而影响硫酸生产过程,引发火灾事故。
4. 配套设施缺陷硫酸生产过程中,配套设施的缺陷可能会引发火灾事故,比如泄漏阀门、管道腐蚀等。
三、硫酸火灾事故的危害1. 对人身安全的威胁硫酸火灾事故会对生产工人的人身安全造成威胁,可能引发化学灼伤或中毒。
2. 对环境的污染硫酸火灾事故除了对人身安全构成威胁外,还会对周围环境造成严重的污染,影响周围居民的生活和健康。
3. 生产设备的损坏硫酸火灾事故会对生产设备造成损坏,从而影响生产的正常进行。
四、硫酸火灾事故的应急处理1. 迅速通知应急救援队伍一旦发生硫酸火灾事故,应立即通知所属行政区、应急救援队伍,迅速组织人员进行灭火、救援工作。
2. 停止硫酸生产在火灾事故发生后,应立即停止硫酸生产,确保火灾不会扩大蔓延。
3. 撤离受影响区域一旦发生硫酸火灾事故,应立即撤离受影响区域的人员,确保人员生命安全。
4. 采取有效的灭火措施对于硫酸火灾,应采取适当的灭火措施,如使用干粉灭火器或二氧化碳灭火器等。
五、硫酸火灾事故的防范措施1. 定期检查设备对硫酸生产设备进行定期检查和维护,确保设备正常运行,防止设备故障引发火灾。
工业硫酸测定实验报告
实验名称:工业硫酸含量的测定一、实验目的1. 熟悉工业硫酸含量的测定方法。
2. 掌握滴定实验的基本操作和注意事项。
3. 提高对实验数据的处理和分析能力。
二、实验原理工业硫酸含量测定采用酸碱滴定法,以氢氧化钠标准溶液为滴定剂,甲基红-次甲基蓝混合指示剂为指示剂。
当氢氧化钠与硫酸反应完全时,溶液颜色由紫红变为灰绿色,此时滴定达到终点。
根据消耗的氢氧化钠溶液的体积和浓度,可以计算出硫酸的含量。
三、实验仪器与试剂1. 仪器:滴定管、锥形瓶、移液管、烧杯、玻璃棒、电子天平、温度计、量筒等。
2. 试剂:氢氧化钠标准溶液(c(NaOH) 0.5 mol/L)、甲基红-次甲基蓝混合指示剂、浓硫酸、蒸馏水等。
四、实验步骤1. 准备氢氧化钠标准溶液:将氢氧化钠固体溶解于少量蒸馏水中,转移至1000mL容量瓶中,用蒸馏水定容至刻度,摇匀。
2. 准备甲基红-次甲基蓝混合指示剂:取甲基红和次甲基蓝指示剂各1 g,溶于少量蒸馏水中,转移至100 mL容量瓶中,用蒸馏水定容至刻度,摇匀。
3. 准备待测溶液:准确称取0.7 g工业硫酸试样(精确至0.0001 g),转移至250 mL锥形瓶中,加入50 mL蒸馏水,搅拌溶解,冷却至室温。
4. 滴定:用移液管移取25 mL待测溶液于锥形瓶中,加入2-3滴甲基红-次甲基蓝混合指示剂,用氢氧化钠标准溶液滴定至溶液呈灰绿色为终点。
5. 计算硫酸含量:根据消耗的氢氧化钠溶液的体积和浓度,按照公式计算硫酸的质量分数。
五、实验数据与结果1. 氢氧化钠标准溶液的体积:V(NaOH) = 20.00 mL2. 氢氧化钠标准溶液的浓度:c(NaOH) = 0.5 mol/L3. 待测溶液的体积:V(待测) = 25 mL4. 待测溶液的质量:m(待测) = 0.7 g5. 硫酸的摩尔质量:M(H2SO4) = 98.08 g/mol根据公式计算,硫酸的质量分数为:P(H2SO4) = 100 × [V(NaOH) × c(NaOH) × M(H2SO4)] / (V(待测) × m(待测))P(H2SO4) = 100 × [20.00 mL × 0.5 mol/L × 98.08 g/mol] / (25 mL × 0.7 g)P(H2SO4) ≈ 98.95%六、实验结果分析本次实验中,工业硫酸的质量分数为98.95%,与理论值(98%)基本相符。
硫酸分析报告
硫酸分析报告简介硫酸(H2SO4)是一种常见的无机酸,广泛应用于工业生产和实验室研究中。
本分析报告将介绍硫酸的基本性质、常见的分析方法以及实验结果分析。
通过本报告,您将了解到硫酸的性质特点以及如何进行准确的分析。
硫酸的基本性质硫酸是一种无色、无味的液体,常见的浓度为98%,其化学式为H2SO4。
硫酸具有强酸性,可以与许多物质发生反应,包括金属和非金属物质。
硫酸在常温下呈现为沉淀的固体硫酸的形式。
硫酸可以通过硫矿石的氧化反应得到,也可以通过硫的燃烧反应得到。
硫酸在工业上广泛应用于金属加工、肥料生产、废水处理和化学实验室等领域。
硫酸的常见分析方法酸度测定硫酸的酸度测定是分析硫酸浓度的常见方法之一。
常用的方法有酸碱滴定法和酸度计测定法。
酸碱滴定法是通过滴定一定浓度的碱溶液来测定硫酸的酸性。
首先,将一定量的硫酸与酸性指示剂染色,然后用硷溶液逐滴加入,直到溶液的酸性消失为止。
根据滴定所需的硷溶液的体积和浓度,可以计算出硫酸的浓度。
酸度计测定法是使用酸度计来测定硫酸的酸性。
通过将一定量的硫酸溶液放入酸度计中,酸度计会自动测定溶液的酸性,并将结果以数字显示出来。
根据酸度计测得的数值,可以计算出硫酸的浓度。
化学分析法化学分析法是通过化学反应来确定硫酸的浓度。
常见的化学分析方法有重量法、容量法和量热法等。
重量法是通过测量一定体积的硫酸溶液的重量来计算其浓度。
首先,称取一定体积的硫酸溶液,并将其蒸发至干燥,然后称取干燥后的硫酸溶液的重量。
根据测得的重量和溶液的体积,可以计算出硫酸的浓度。
容量法是通过滴定一定体积的硫酸溶液来测定其浓度。
首先,用溶液的体积和浓度知道硷溶液的浓度和酸性,然后将硷溶液逐滴加入硫酸溶液中,直到溶液的酸性消失为止。
根据滴定所需的硷溶液的体积和浓度,可以计算出硫酸的浓度。
量热法是通过测量硫酸与其他物质之间反应的放热量来确定其浓度。
实验结果分析酸度测定实验结果分析在酸碱滴定法实验中,滴定所需的碱溶液的体积和浓度可以用于计算硫酸的浓度。
(ASTM协会)硫酸分析标准
Designation:E223–96(Reapproved2002)e1Standard Test Methods forAnalysis of Sulfuric Acid1This standard is issued under thefixed designation E223;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1N OTE—The value for the95%range for Repeatability of0.004%NVM was changed from0.007to0.0023in Table2in June2003.1.Scope1.1These test methods cover the analysis of sulfuric acid.1.2The analytical procedures appear in the following order:SectionsTotal Acidity8to16BauméGravity17to26 Nonvolatile Matter27to33Iron34to43Sulfur Dioxide44to51Arsenic52to611.3This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Specific hazards statements are given in Section5.2.Referenced Documents2.1ASTM Standards:D1193Specification for Reagent Water2E1Specification for ASTM Thermometers3E60Practice for Analysis of Metals,Ores,and Related Materials by Molecular Absorption Spectrometry4E180Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial Chemicals5 E200Practice for Preparation,Standardization,and Stor-age of Standard and Reagent Solutions for Chemical Analysis53.Significance and Use3.1These test methods provide for the classification of various grades of sulfuric acid and for the determination of various impurities.Acid strength and impurity levels are important factors in many uses of sulfuric acid.4.Purity of Reagents4.1Purity of Reagents—Reagent grade chemicals shall be used in all tests.Unless otherwise indicated,it is intended that all reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society, where such specifications are available.6Other grades may be used,provided it isfirst ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.4.2Purity of Water—Unless otherwise indicated,references to water shall be understood to mean Type II or Type III reagent water conforming to Specification D1193.5.Hazards5.1Sulfuric acid is a strong corrosive acid and is dangerous if improperly handled.Avoid any skin or eye contact.5.2Clean up all spills immediately by covering the spill with vermiculite or some other inert absorbent material and sweeping into a pan.Dispose of the absorbent byflooding with water and discarding in a suitable container.Flush the area with water.6.Photometers and Photometric Practice6.1Photometers and the photometric practice used in these test methods shall conform to Practice E60.7.Sampling7.1Sampling of sulfuric acid is not within the scope of these test methods.7.2The sample to be analyzed shall be considered to be that sample in a single bottle submitted to the analytical laboratory.1These test methods are under the jurisdiction of ASTM Committee E15on Industrial and Specialty Chemicals and are the direct responsibility of Subcommit-tee E15.02on Product Standards.Current edition approved Oct.10,2002.Published February2003.Originally approved st previous edition approved in1996as E223–96.2Annual Book of ASTM Standards,V ol11.01.3Annual Book of ASTM Standards,V ol14.03.4Annual Book of ASTM Standards,V ol03.05.5Annual Book of ASTM Standards,V ol15.05.6Reagent Chemicals,American Chemical Society Specifications,American Chemical Society,Washington,DC.For suggestions on the testing of reagents not listed by the American Chemical Society,see Analar Standards for Laboratory Chemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeia and National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville, MD.1Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.7.3The size of the sample shall be sufficient to perform all analyses without the reuse of any portion of the sample.TOTAL ACIDITY8.Scope8.1This test method covers the determination of the total acidity of 75to 99%sulfuric acid.Two test methods are given for weighing the sample,namely,the Dely tube and the snake tube test methods.9.Summary of Test Method9.1A weighed sample of acid is diluted in water and titrated with standardized 0.5N sodium hydroxide solution,using phenolphthalein as the indicator.10.Interferences10.1Acids other than sulfuric and compounds that consume sodium hydroxide will affect the accuracy of this test method.11.Apparatus11.1Dely Tube (Fig.1)or Snake Tube (Fig.2).711.2Buret ,100-mL,Class A,bulb-type.12.Reagents12.1Phenolphthalein Indicator Solution (10g/L)—Dissolve 1g of phenolphthalein in 100mL of ethanol (95%),methanol,or isopropanol.812.2Sodium Hydroxide,Standard Solution (0.5N )—See Practice E 200.13.Procedure13.1Dely Tube Test Method —Invert the sample bottle several times.(Hold the stopper in tight.)Insert the long arm of a dry,weighed Dely tube and withdraw by suction a convenient size sample depending upon the acid strength as given in Table 1(Note 1).Invert the Dely tube and wipe the acid from the long arm with disposable tissue several layers thick.Discard the tissue immediately to avoid burning the fingers.Reweigh to the nearest 0.0001g and record the weight of the sample.Incline the tube so that the acid runs back nearly to the bend of the short arm.Attach the short arm to an elevated water reservoir by means of a rubber tube closed near the lower end with a pinch clamp.Insert the long arm of the Dely tube into 400-mL glass beaker containing approximately 100mL of water.Open the pinch clamp and flush the sample into the beaker.Continue the flow of water until all acid is washed from the Dely Tube (Note 2and Note 3).Wash the long end of the Dely tube,collecting the washings in the beaker.Add 3to 5drops of phenolphthalein indicator solution.Record the tem-perature of the 0.5N NaOH solution,and then titrate the sample to a pink end point.Record the titration to the nearest 0.02mL.N OTE 1—The Dely tube can be marked at points equivalent to weights given in Table 1.7Suitable Dely and snake tubes are available from Corning Glass Works,Corning,NY .8This reagent is also described in Practice E200.FIG.1DelyTubeFIG.2Snake TubeTABLE 1Sample Size for Total AcidityH 2SO 4,%Sample Size,g 98 1.9to 2.294 2.0to 2.390 2.1to 2.485 2.2to 2.680 2.3to 2.777 2.4to 2.8752.5to2.9N OTE2—The presence of acid in the Dely tube may be detected by coloring the water in the reservoir with phenolphthalein indicator and the minimum amount of dilute NaOH solution that will produce a slight pink. The waterflowing through the tube is dicolorized as long as acid is present,and the appearance of a pink color indicates the absence of acid. N OTE3—The acid and water are separated by a bubble of air.13.2Snake Tube Test Method—Invert the sample bottle several times.(Hold the stopper in tight).Insert the capillary end of a dry,weighed snake tube and withdraw by suction a convenient size sample depending upon the acid strength as given in Table1.Invert the tube so that the double bend is in a horizontal position.Wipe the acid from the capillary with disposable tissue several layers thick.Discard the tissue immediately to avoid burning thefingers.Reweigh to the nearest0.0001g and record the weight of the sample.Sub-merge the capillary of the tube in approximately100mL of water contained in the400-mL beaker.Force the weighed sample from the tube by a stream of water from a wash bottle by placing the delivery tip in the exposed end of the snake tube (Note4).Wash the tube with50to70mL of water.Remove the tube and wash the outside free of acid.Swirl the contents of the beaker gently while washing.Accumulate all washings in the beaker and add3to5drops of phenolphthalein indicator solution.Record the temperature of the0.5N NaOH solution, and then titrate the sample to a pink end point.Record the titration to the nearest0.02mL.N OTE4—Do not introduce the water into the snake tube too rapidly,as this will cause spattering.14.Calculation14.1If necessary,correct the buret reading for calibration errors and record the volume of titrant as V and the temperature as t.14.2Correct the normality of the sodium hydroxide stan-dard solution for any difference in temperature between time of standardization and time of use according to the following equation:N5N s10.00014~s2t!(1) where:N=normality of NaOH solution at temperature t during use,N s=normality of NaOH solution at temperature s during standardization,s=temperature of NaOH solution during standardization, andt=temperature of NaOH solution during analysis.14.3Calculate the total acidity as percentage of sulfuric acid as follows:Sulfuric acid,wt%5~VN30.04904!W3100(2)where:V=corrected millilitre of NaOH solution required for titration of the sample,N=normality of the NaOH solution,andW=grams of sample used.15.Report15.1Report the percentage of sulfuric acid to the nearest 0.01%.16.Precision and Bias16.1The following criteria should be used for judging the acceptability of results(see Note5):16.1.1Repeatability(Single Analyst)—The standard devia-tion for a single determination has been estimated to be 0.069%absolute at56df.The95%limit for the difference between two such runs is0.19%absolute.16.1.2Laboratory Precision(Within-Laboratory,Between-Days Variability),Formerly Called Repeatability—The stan-dard deviation of results(each the average of duplicates), obtained by the same analyst on different days,has been estimated to be0.104%absolute at28df.The95%limit for the difference between two such averages is0.29%absolute.16.1.3Reproducibility(Multilaboratory)—The standard de-viation of results(each the average of duplicates),obtained by analysts in different laboratories,has been estimated to be 0.124%absolute at7df.The95%limit for the difference between two such averages is0.35%absolute.N OTE5—These precision estimates are based on an interlaboratory study of analyses performed in1963on three samples containing approximately80,90,and95%sulfuric acid.One analyst in each of ten laboratories performed duplicate determinations and repeated one day later,for a total of120determinations.9Practice E180was used in developing these precision estimates.16.2Since there is no accepted reference material for determining the bias for measuring the total acidity of sulfuric acid,the bias of this test method has not been determined.BAUMÉGRA VITY17.Scope17.1This test method covers the determination of the Baumégravity of concentrated sulfuric acid by means of a glass hydrometer in the range from57to66.2°Baumé.The Baumégravity is determined at15.5°C(60°F).This test method is not applicable to readings above66.2Baumégravity units.18.Definition18.1BauméGravity—a unit of density based on specific gravity and defined by the following equation:Baumégravity51452@145/sp gr#at15.5/15.5°C~60/60°F!(3) 19.Summary of Test Method19.1A sample of sulfuric acid is placed in a hydrometer cylinder and when the temperature is constant,the Baumégravity is read from the glass hydrometer.20.Significance and Use20.1The Baumégravity is used to classify various grades of sulfuric acid.This test method is not applicable for accurate determinations of the concentration of sulfuric acid.9Details of the interlaboratory study are available from ASTM International Headquarters.Request RR:E15-1047.21.Apparatus21.1Hydrometer,10streamline or torpedo design,precision grade for liquids heavier than water in ranges from 57to 62°Béand 63to 67°Bé.The total length shall be approximately 12in.(305mm)divided to 0.05°Béover a 6-in.(152-mm)(approximate)scale and standardized at 15.5/15.5°C (60/60°F)with a tolerance of 0.05°Béthroughout.The modulus is as follows:Bé51452@145/sp gr #at 15.5/15.5°C ~60/60°F !(4)Each of the hydrometers shall show on the scale the modulus.21.2Thermometer ,having a range from −2to +80°C (30to 180°F)and conforming to the requirements for Thermom-eter 15C (15F)as prescribed in Specification E 1.21.3Cylinder,Hydrometer ,glass,with or without lip,diam-eter 38to 40mm,height 325to 375mm.22.Temperature of Test22.1Baumégravity shall be determined at 15.560.3°C (6060.5°F).23.Procedure23.1Rinse a clean hydrometer cylinder with the sample to be tested,add the sample,and adjust the temperature to 15.560.3°C (6060.5°F).Place the cylinder in a vertical position in a location free of air currents.Insert the hydrometer in the sample.Push it down about 3mm below the level at which it will float and release it.Read the hydrometer when it has come to rest,floating freely,and the temperature is 15.5°C (60°F).The correct reading is that point on the hydrometer scale at which the surface of the liquid cuts the scale.Determine this point by placing the eye slightly below the level of the liquid and slowly raising it until the surface,first seen as a distorted ellipse,appears to become a straight line cutting the hydrom-eter scale.Record as Baumégravity.24.Calculation24.1Calculate the specific gravity for later calculations in accordance with the following equation:sp gr 51451452Be ´(5)25.Report25.1Report the Baumégravity to the nearest 0.01unit.26.Precision and Bias26.1The following criteria should be used for judging the acceptibility of results (see Note 6):26.1.1Repeatability (Single Analyst)—The standard devia-tion for a single determination has been estimated to be 0.018unit absolute at 48df.The 95%limit for the difference between two such runs is 0.05unit absolute.26.1.2Laboratory Precision (Within-Laboratory,Between-Days Variability),Formerly Called Repeatability —The stan-dard deviation of results (each the average of duplicates),obtained by the same analyst on different days,has been estimated to be 0.016unit absolute at 24df.The 95%limit for the difference between two such averages is 0.045unit abso-lute.26.1.3Reproducibility (Multilaboratory)—The standard de-viation of results (each the average of duplicates),obtained by analysts in different laboratories,has been estimated to be 0.063unit absolute at 7df.The 95%limit for the difference between two such averages is 0.18unit absolute.N OTE 6—These precision estimates are based on an interlaboratory study of analyses performed in 1963on three samples having Baumégravities of approximately 61,65,and 66units.One analyst in each of nine laboratories performed duplicate determinations and repeated one day later,for a total of 104determinations.9Practice E 180was used in developing these precision estimates.26.2Since there is no accepted reference material for determining the bias for measuring the Baumégravity of sulfuric acid,the bias of this test method has not been determined.NONVOLATILE MATTER27.Scope27.1This test method covers the gravimetric determination of nonvolatile matter in sulfuric acid.The lower limit of determination of nonvolatile matter is 0.001%.28.Summary of Test Method28.1A weighed sample of acid is evaporated,ignited,and the residue weighed.29.Apparatus29.1Evaporating Dish ,platinum or high-silica glass,150-mL.29.2Muffle Furnace ,maintained at 800625°C (1472645°F).29.3Crucible Tongs .30.Procedure30.1Clean a platinum or a high-silica glass dish (Note 7and Note 8)and ignite in a muffle furnace at 800625°C (1472645°F)for at least 10min.Cool in a desiccator to room temperature and weigh the dish to the nearest 0.1mg (Note 9).N OTE 7—New platinum or high-silica glass dishes should be boiled in HCl (1+1)for 10min,washed,and ignited in the muffle furnace for at least 1h before their first use.N OTE 8—High-silica glass dishes should be used only for low nonvola-tile material.The residue remaining from samples containing large amounts of nonvolatile matter may fuse into the dish.N OTE 9—High-silica glass dishes should be allowed to cool at least 45min and platinum dishes at least 20min before weighing.30.2Mix the sample by inverting the sample bottle repeat-edly until all solids are in suspension.N OTE 10—It is important that the sample be well mixed and that all solids are in homogeneous suspension so that a representative sample can be obtained.10Suitable hydrometers are available from Walter H.Kessler,Inc.,160Hicks St.,Westbury,L.I.,NY11590.30.3Transfer a weighed sample containing a minimum of 50g,weighed to the nearest 0.1g,or a weighed sample of sufficient size to yield not less than 1mg of residue,to the evaporating dish and evaporate to dryness over a burner or hot plate in a hood.After evaporation,ignite the sample in the muffle furnace for e crucible tongs in handling the evaporating dish at all times.30.4Allow the dish to cool to room temperature in a desiccator and rapidly weigh the sample dish to the nearest 0.1mg.31.Calculation31.1Calculate the percentage of nonvolatile matter as follows (Note 11):Nonvolatile matter,wt %5~R 2D !W 3100(6)where:R =weight of evaporating dish and residue,g,D =weight of evaporating dish,g,and W =sample used,g.N OTE 11—If this value is less than 0.0010%,report as less than 0.0010%.32.Report32.1Report the percentage of nonvolatile matter to the nearest 0.0001%.33.Precision and Bias33.1The following criteria should be used for judging the acceptibility of results (see Note 12):33.1.1Repeatability (Single Analyst)—The standard devia-tion for a single determination has been estimated to be the value in Table 2at the indicated degrees of freedom.The 95%limit for the difference between two such runs is given in Table 2.33.1.2Laboratory Precision (Within-Laboratory,Between-Days Variability),Formerly Called Repeatability —The stan-dard deviation of results (each the average of duplicates),obtained by the same analyst on different days,has been estimated to be the value in Table 2at the indicated degrees of freedom.The 95%limit for the difference between two such averages is given in Table 2.33.1.3Reproducibility (Multilaboratory)—The standard de-viation of results (each the average of duplicates),obtained by analysts in different laboratories,has been estimated to be the value given in Table 2at the indicated degrees of freedom.The 95%limit for the difference between two such averages is given in Table 2.N OTE 12—These precision estimates are based on an interlaboratory study of analyses performed in 1963–1964on five samples containing approximately 0.003,0.005,0.010,0.014,0.024,and 0.048%nonvolatile matter.One analyst in each of eight to ten laboratories performed duplicate determinations and repeated one day later.9Practice E 180was used in developing these precision estimates.33.2Since there is no accepted reference material for determining the bias for measuring the nonvolatile matter of sulfuric acid,the bias of this test method has not been determined.IRON34.Scope34.1This test method describes the determination of iron in sulfuric acid.The lower limit of determination of iron is 0.0001%.35.Summary of Test Method35.1The iron is reduced and determined colorimetrically with 1,10-phenanthroline (ortho -phenanthroline),which forms an orange-red complex with ferrous iron.The intensity of the color so formed is measured in a photometer calibrated with standard iron solutions.36.Interferences36.1It is beyond the scope of this test method to describe procedures for overcoming all possible interferences that may be encountered.Chromium interferes if it is present in suffi-cient quantity for the color of chromic ion to have a masking effect.Copper,antimony,cobalt,mercury (I),and tin (II,IV)interfere in concentrations of 10to 50ppm.Cadmium,mercury (II),zinc,and nickel may interfere,but can be overcome by the use of excess 1,10-phenanthroline reagent.37.Apparatus37.1Photometer —Any photoelectric spectrophotometer or filter photometer that will measure the absorbance of the solutions in the wavelength range from 500to 525nm.37.2Absorption Cells ,2-cm light path.N OTE 13—This procedure has been written for a cell having a 2-cm light path.Cells having other dimensions may be used,provided suitable adjustments can be made in the amounts of sample and reagents used.38.Reagents38.1Ammonium Acetate–Acetic Acid Solution —Dissolve 100g of ammonium acetate (CH 3COONH 4)in about 600mL of water,filter,add 200mL of glacial acetic acid to the filtrate,and dilute to 1L.TABLE 2Nonvolatile Matter Precision ValuesNVM,%RepeatabilityLaboratory PrecisionReproducibility Standard Deviation Degrees of Freedom95%Range Standard Deviation Degrees of Freedom95%Range Standard Deviation Degrees of Freedom95%Range 0.0030.0004220.00100.0004110.00100.0015100.00400.0040.0008160.00230.000780.00190.001370.00360.01to 0.0240.0015540.00420.0009270.00240.001370.00360.0480.0009200.00250.0013100.00360.004690.013038.2Ammonium Hydroxide Solution(1+1)—Dilute to500 mL of ammonium hydroxide(NH4OH)with500mL of water, and mix.838.3Congo Red Paper.38.4Hydroxylamine Hydrochloride Solution(100g/L)—Dissolve100g of hydroxylamine hydrochloride(NH2OH·HCl) in about600mL of water,filter,and dilute to1L.838.5Iron,Standard Solution(1mL=0.01mg Fe)11—See Practice E200.38.61,10-Phenanthroline(o-Phenanthroline)Solution(3 g/L)—Dissolve3g of ortho-phenanthroline monohydrate in 500mL of water,add1mL of hydrochloric acid(HCl),mix,filter,and dilute to1L.839.Calibration39.1To a series of100-mL volumetricflasks,pipet0,2,4, 8,and10mL of standard iron solution.To eachflash add the following reagents in order,mixing after addition of each:20 mL of water,1mL of hydroxylamine hydrochloride solution,5 mL of1,10-phenanthroline solution,and NH4OH(1+1)as required to bring the pH to3.5to4.0(just alkaline to Congo red paper).Add5mL of ammonium acetate solution,dilute to the mark with water,mix thoroughly,and allow to stand approximately15min.39.2Measure the absorbances of the solutions using a photometer with a wavelength setting of510nm or afilter photometer equipped with afilter in the range from500to525 nm,adjusting the photometer to read zero absorbance for the reagent blank.39.3Plot on coordinate paper the absorbances of the cali-bration solutions against milligrams of iron present per100mL of solution.40.Procedure40.1Mix the sample by inverting the sample bottle until all solids are in suspension(Note10).40.2Insert a70-mm stem funnel in a100-mL volumetric flask and add50mL of water(Note14).Remove the funnel and slowly add,with continual swirling of the contents of the flask,1g of sample weighed by difference to the nearest0.001 g.Wash down the neck of theflask with approximately5mL of water.N OTE14—This is done to keep the neck of theflask dry and prevent spitting or spattering on introducing the sample.40.3Add to theflask the following reagents in order,mixing after the addition of each:1mL of hydroxylamine hydrochlo-ride solution,5mL of1,10-phenanthroline solution,and NH4OH(1+1)as required to bring the pH of the solution to 3.5to4.0(just alkaline to Congo red paper).Add5mL of ammonium acetate solution,dilute to the mark with water,mix thoroughly,and allow to stand approximately15min.40.4Prepare a blank solution using all reagents but omitting the sample.Allow to stand about15min.40.5Determine the absorbance of the sample at the same wavelength used for the calibration curve,blanking the instru-ment at zero absorbance with the blank solution.Determine from the calibration curve the milligrams of iron that corre-spond to the observed absorbance of the sample.N OTE15—If the color obtained is too intense to fall within the range of the calibration curve,repeat with a smaller sample.N OTE16—If the color obtained is less than that obtained with0.01mg of iron,repeat as follows:Transfer10g of sample,weighed by difference to the nearest0.01g,to a50-mL beaker and evaporate almost to dryness over a burner or hotplate in a hood.Cool.Add10mL of water and2mL of HCl(sp gr1.19)and heat to dissolve any solids.Transfer the solution to a100-mL volumetricflask with a minimum amount of water and proceed in accordance with40.3starting with the addition of1mL of hydroxylamine hydrochloride solution.41.Calculation41.1Calculate the percentage of iron as follows(Note17):Iron,wt%5MW310003100(7)where:M=iron,found from calibration curve,mg,andW=sample used,g.N OTE17—If this value is less than0.0001%,report as less than 0.0001%.42.Report42.1Report the percentage of iron to the nearest0.0001%.43.Precision and Bias43.1The following criteria should be used for judging the acceptibility of results(see Note18):43.1.1Repeatability(Single Analyst)—The standard devia-tion for a single determination has been estimated to be 0.00018%absolute at52df.The95%limit for the difference between two such runs is0.0005%absolute.43.1.2Laboratory Precision(Within-Laboratory,Between-Days Variability),Formerly Called Repeatability—The stan-dard deviation of results(each the average of duplicates), obtained by the same analyst on different days,has been estimated to be0.00021%absolute at26df.The95%limit for the difference between two such averages is0.0006%abso-lute.43.1.3Reproducibility(Multilaboratory)—The standard de-viation of results(each the average of duplicates),obtained by analysts in different laboratories,has been estimated to be 0.00034%absolute at6df.The95%limit for the difference between two such averages is0.0009%absolute.N OTE18—These precision estimates are based on an interlaboratory study of analyses performed in1963–1964on three samples containing approximately0.004,0.005,and0.008%iron.One analyst in each of nine laboratories performed duplicate determinations and repeated one day later,for a total of108determinations.9Practice E180was used in developing these precision estimates.One sample,containing approximately0.0003%iron and analyzed by one analyst in each of eight laboratories for a total of32determinations, gave the following precision data:Repeatability(Single Analyst)—The standard deviation for a single determination has been estimated to be0.000041%absolute at16df.The 95%limit for the difference between two such runs is0.0001%absolute. Laboratory Precision(Within-Laboratory,Between-Days Variability), Formerly Called Repeatability—The standard deviation of results(each11This reagent is used for calibrating purposesonly.the average of duplicates),obtained by the same analyst on different days, has been estimated to be0.000051%absolute at8df.The95%limit for the difference between two such averages is0.0001%absolute. Reproducibility(Multilaboratory)—The standard deviation of results (each the average of duplicates),obtained by analysts in different laboratories,has been estimated to be0.00014%absolute at7df.The 95%limit for the difference between two such averages is0.0004% absolute.43.1.4Above0.01%iron,the precision is poor because of difficulty in sampling.43.2Since there is no accepted reference material for determining the bias for measuring the iron content of sulfuric acid,the bias of this test method has not been determined.SULFUR DIOXIDE44.Scope44.1This test method covers the determination of free sulfur dioxide dissolved in sulfuric acid.The lower limit of determination of sulfur dioxide is0.002%.45.Summary of Test Method45.1The sulfur dioxide is swept out of the sample of sulfuric acid by means of a current of nitrogen gas.The evolved sulfur dioxide is absorbed in an alkaline solution, treated with an excess of iodate-iodide solution and the excess is titrated with sodium thiosulfate.46.Apparatus46.1Evolution and Absorption Train,consisting of:46.1.1Source of Pure Nitrogen Gas,connected to46.1.2Drechsel Gas-Washing Bottle,125-mL,connected asa safety trap to prevent acid suck-back,connected to46.1.3Drechsel Gas-Washing Bottle,125-mL,with fritted glass disk on the inlet tube,connected to46.1.4Drechsel Gas-Washing Bottle,250-mL,with fritted glass disk on the inlet tube.47.Reagents47.1Potassium Iodate-Potassium Iodide Solution(approxi-mately0.1N)—Dissolve4g of potassium iodate(KIO3)and 100g of potassium iodide(KI)in water and dilute to1L with water.47.2Sodium Hydroxide Solution(4g/L)—Dissolve4g of sodium hydroxide(NaOH)in water and dilute to1L.847.3Sodium Thiosulfate,Standard Solution(0.1N)—See Practice E200.47.4Sodium Thiosulfate,Standard Solution(0.01N)—Pipet100mL of0.1N sodium thiosulfate(Na2S2O3)solution into a1-L volumetricflask,dilute to volume with water,and mix.The normality is exactly one tenth that of the0.1N solution.47.5Starch Indicator Solution(10g/L)—Mix1g of soluble starch with5mg of red mercuric iodide(HgI2)and enough cold water to make a thin paste,and pour slowly,with constant stirring,into100mL of boiling water.Boil the mixture while stirring until a thin,translucentfluid is obtained.Cool before use.847.6Sulfuric Acid(1+5)—Mix carefully while stirring,1 volume of concentrated sulfuric acid(H2SO4,sp gr1.84)with 5volumes of water.48.Procedure48.1Flush out the safety bottle with nitrogen.48.2From a graduated cylinder,transfer about50mL of the sample into the125-mL Drechsel bottle and connect to the safety bottle.Note the millilitres of sample used,W.48.3Place about100mL of the NaOH solution in250-mL Drechsel bottle and connect to the125-mL Drechsel bottle.48.4Pass nitrogen gas through the apparatus at about20L/h for3h.48.5Disconnect the bottle containing the NaOH solution and turn off the nitrogenflow.Rinse the bubbler tube with water into the bottle,pipet5mL of the KIO3-KI solution into the bottle,and mix.48.6Add5mL of H2SO4(1+5)and2mL of the starch indicator solution and titrate with the0.01N Na2S2O3solution until the blue color is discharged.Record the volume of Na2S2O3solution used,A.(If no blue color is evident,repeat the procedure with25mL of sample.)48.7Repeat the entire procedure,substituting50mL of water for the sample in the125-mL Drechsel bottle.Record the volume of Na2S2O3solution used,B.48.8If the back titration of the sample solution requires more than30mL of the Na2S2O3solution repeat both the blank and sample determinations,using only2mL of the KIO3-KI solution.49.Calculation49.1Calculate the percentage of sulfur dioxide as follows (Note19):Sulfur dioxide,wt%5~B2A!3N30.032W3sp gr3100(8)where:B=Na2S2O3solution required for the titration of the blank solution,mL,A=Na2S2O3solution required for the titration of the sample solution,mL,N=normality of the Na2S2O3solution,andW=sample used,mL.N OTE19—If this value is less than0.002%,report as less than 0.002%.50.Report50.1Report the percentage of sulfur dioxide to the nearest 0.001%.51.Precision and Bias51.1The following criteria should be used for judging the acceptibility of results(see Note20):51.1.1Repeatability(Single Analyst)—The coefficient of variation for a single determination has been estimated to be 10.1%relative at42df.The95%limit for the difference between two such runs is28%relative.。
环境风险分析(硫酸)
环境风险分析1 硫酸生产危险因素分析在硫酸生产、储运过程中,由于生产设备、工艺的原因,人为的或不可抗拒的原因,导致废气超标排放和硫酸泄漏,造成的事故有可能对环境造成危害。
①在生产过程中开车生产、工艺或设备出现问题都有可能造成硫酸生产尾气中二氧化硫和三氧化硫超标排放。
硫酸储存设备与装置由于受损或人员违规操作等原因造成硫酸泄漏,可能造成大量硫酸雾排放。
后果会危及周围人群的健康和生命安全;硫酸雾会毁坏周围的植物及植被,腐蚀附近建筑物。
②在火车、汽车装卸和运输过程中如发生浓硫酸泄漏,可能造成以下后果:硫酸及酸雾会危及周围人群的健康和生命安全;硫酸泄漏后渗入土壤会造成土壤酸性;硫酸雾在空气中扩散污染环境空气,酸雾会毁坏周围的植物及植被,腐蚀周围建筑物。
硫酸如果直接流入地表水中会污染水域;导致水中动植物死亡;浓硫酸遇水引起强烈反应,会产生浓烈的硫酸烟雾。
影响周围环境空气,危及周围人群的健康和生命安全。
本次评价根据硫酸生产工艺、装置和生产储运情况分析,通过对硫酸造成的安全环境污染事故调查,硫酸生产在厂区内的主要环境危险因素是SO2、SO3、硫酸雾废气的非正常和事故排放,本次评价主要对SO2、SO3、硫酸雾废气非正常和事故排放对空气环境的影响进行预测和防范措施分析,对浓硫酸大量泄漏对空气可能产生的影响进行定性分析和防范措施分析,根据该厂生产、储存设施情况,废水处理装置情况,对浓硫酸大量泄漏,或停车冲洗废水的处理情况进行分析。
环境风险评价中往往是通过对历史事故的调查,最好是全世界或国内同类项目运行的历史的事故调查来确定事故可能发生的概率。
关于硫酸生产、储运中发生非正常排放和事故排放的报道较少,尤其是危害事故的报道不完整,因此很难从历史事故调查分析中确定事故可能发生的概率。
本次评价重点对污染排放的原因、源强及其影响情况进行分析。
提出相应的防范措施。
2 主要污染物物化毒理性质2.1二氧化硫2.1.1理化特性分子式:SO2;分子量:64.07;性状:常温下无色气体,具辛辣和窒息气味,在常温时压力(4~5kg/cm2)下压缩为无色、流动的液体。
硫酸分析纯工艺流程
噫,汝欲以文言述说硫酸分析纯之工艺流程,此诚为化学之奥秘,非易言也。
然吾试为汝解之。
夫硫酸分析纯者,务在提纯硫酸,去其杂质,以致纯净无瑕。
其工艺之流程,首在选材,必选优质之硫铁矿,或他种含硫之矿物,以为原料。
既得原料,乃以煅烧之法,炼出二氧化硫气体。
此气体经过净化、干燥,而后通入接触室,与氧气反应,生成三氧化硫。
三氧化硫者,性甚活泼,易与水化合。
故以浓硫酸吸收之,生成发烟硫酸。
此发烟硫酸,再经过稀释、冷却、结晶、过滤等步骤,乃得纯净之硫酸分析纯。
此工艺流程,虽简述之,然其中每一步骤,皆需精细操作,严格控制条件,以确保产品质量。
吾人当致知在格物,穷理尽性,以探化学之奥秘,利天下而济苍生。
硫酸的检测方法
硫酸的检测方法
硫酸是一种常见的无机化合物,广泛应用于工业生产和科学研究中。
以下是几种常见的检测方法:
1. 工业分析法:将待测样品与铅盐溶液反应,生成白色的沉淀,然后加入乙醇和亚硫酸钠溶液,再加入克氏发黑剂,观察是否产生蓝紫色的沉淀。
如果出现沉淀则说明样品中含有硫酸。
2. 离子色谱法:利用离子交换树脂将待测样品中的离子分离并排除干扰,然后通过色谱柱进行分离和检测,以得出硫酸的浓度。
3. 重量分析法:将待测样品与过量的钡盐反应,生成固体沉淀,然后过滤、洗涤、烘干和称量,最终计算出硫酸的质量。
4. 比重法:利用硫酸具有较高密度的特点,通过比重测定来判断样品中是否含有硫酸。
5. 比色法:利用硫酸和巴比妥酸钠在碱性条件下的反应,可以通过比色法来定量检测硫酸的浓度。
需要注意的是,不同的检测方法适用于不同的情况和场合,具体的选择需要根据实际需求来确定。
硫酸生产安全风险分析
硫酸生产安全风险分析姓名:XXX部门:XXX日期:XXX硫酸生产安全风险分析硫酸是一种重要的基本化工原料,其用途十分广泛,在国民经济中占有举足轻重的地位。
硫酸的主要生产原料为硫磺、硫铁矿、冶炼烟气、硫化氢等,目前主要生产工艺为接触法,包括原料二氧化硫的生成、二氧化硫向三氧化硫的催化转化和三氧化硫的吸收。
由于硫酸生产所涉及的化学物质和工艺过程具有一定的安全风险,所以应引起足够的重视并采取适当的防范措施。
本文对此分析如下。
1硫酸生产中主要化学物质风险分析1.1原料硫酸生产中涉及安全风险的原料主要为硫磺和硫化氢。
1.1.1硫磺硫磺为淡黄色脆性结晶或粉末,可能因含少许硫化氢而有特殊臭味,183.8℃时蒸气压0.13kPa,闪点207℃,熔点119℃,沸点444.6℃,相对体积质量(水为1)2.0,自燃温度232℃,爆炸下限2.3g/m3。
硫磺属易燃固体,遇明火、高热易燃,与氧化剂混合能形成爆炸性混合物。
硫磺粉体与空气可形成爆炸性混合物。
硫磺为不良导体,在干燥状态下会因搅拌、输送和注入等操作产生静电。
硫磺能在肠内部分转化为硫化氢而被吸收,故大量口服可导致硫化氢中毒。
硫磺可引起眼结膜炎、皮肤湿疹,对皮肤有弱刺激性。
生产过程中长期吸人硫磺粉尘一般无明显毒性作用。
硫磺的毒性相对较小,主要危险是粉尘爆炸。
在气候干燥、通风不良的情况下处置硫磺,会造成粉尘富集,达到爆炸极限后在外部能量的作用下引发爆炸。
由于硫磺表面易产生静电积累,更加剧了爆炸的危险。
第 2 页共 9 页1.1.2硫化氢硫化氢是可燃性无色气体,具有典型的臭鸡蛋味,沸点-60.3,相对体积质量(空气为1)为1.19,易溶于水及醇类、二硫化碳、石油溶剂和原油,20℃时蒸气压为1874.5kPa,空气中爆炸极限(体积分数)为4.3%-45.5%,自燃温度260℃。
硫化氢是一种神经毒剂,亦为窒息性和刺激性气体。
硫化氢经粘膜吸收较快,经皮肤吸收甚慢。
急性硫化氢中毒一般发病迅速,出现以脑和(或)呼吸系统损害为主的临床表现,亦可伴有心脏等器官功能障碍。
工业硫酸含量的测定方法
工业硫酸含量的测定方法工业硫酸是广泛应用的重要化学品之一,它被用于制造光伏电池、磁带、矿物提取等领域。
准确测定工业硫酸含量是非常重要的。
本文将介绍10种关于工业硫酸含量的测定方法,并对每种方法进行详细描述。
方法一:酸碱滴定法酸碱滴定法是最常用的一种工业硫酸含量测定方法。
其原理是用一种已知浓度的碱溶液滴入硫酸溶液中,当硫酸完全中和时,反应后产生中性溶液,此时记录滴定液的用量即可。
根据滴定液的用量可以计算出硫酸的浓度。
方法二:重量法重量法是一种直接测定硫酸含量的方法。
首先需要准确称量一定质量的硫酸样品,并进行加热,并在加热的过程中记录其失去的重量。
由于硫酸在高温下是易挥发的,因此在加热的过程中,硫酸样品中的水分和其他杂质都会被蒸发。
通过记录加热前后的质量差异,可以得到硫酸样品的质量和含量。
方法三:荧光分析法荧光分析法是在硫酸溶液中添加荧光试剂,然后通过紫外光激发,观察荧光的强度和颜色来测量硫酸的含量。
荧光分析法相对于其他方法具有灵敏度高、检测限低的优点,适用于较低浓度的硫酸含量。
方法四:红外光谱法红外光谱法是通过分析硫酸分子中的振动频率来确定其含量。
硫酸分子中特定的化学键会在红外光谱中产生特定的振动,因此通过对硫酸样品进行红外光谱分析,可以确定硫酸含量。
方法五:比重法比重法是通过测量硫酸溶液的密度来确定其浓度。
硫酸溶液的密度与其浓度之间有相关性,因此可以通过测量硫酸溶液的密度来推算出其浓度值。
方法六:化学分析法化学分析法是将含硫酸的样品与一种或多种试剂进行反应,以便测定其含量。
其中一些化学分析方法包括还原滴定法、二氧化硫滴定法、氯化银滴定法等,这些方法都是经过历史验证并且得到了广泛应用的。
方法七:电导法电导法是通过测量硫酸溶液中的电导率来确定其含量。
硫酸溶液的电导率与其浓度成正比例关系,因此电导测量可用于粗略检测硫酸含量。
方法八:阴离子交换法阴离子交换法是通过将含硫酸的溶液通过一个阴离子交换柱,然后用溶液来洗脱离子,以测量硫酸的含量。
硫酸测定方法
硫酸分析项目指标硫酸含量%≧灼烧残渣%≦铁%≦一、硫酸含量的测定1、测定原理用氢氧化钠标准溶液中和硫酸,以甲基红为指示剂指示终点(中和反应)。
2、仪器和设备分析天平碱式滴定管50ml 三角烧瓶250ml1N氢氧化钠标准溶液 %甲基红指示滴瓶3、测定方法将硫酸试样倒入干燥的滴瓶中,在分析天平用减量法精确称取1克(19-20滴)试样于盛有150ml蒸馏水的250ml三角烧瓶中,摇匀,加入三滴甲基红指示剂,1N的氢氧化钠标准溶液滴定至橙色,记录消耗氢氧化钠标准溶液的的用量。
4、计算硫酸%=V*N*f**100/m试中:V:滴定硫酸所消耗氢氧化钠的量N:标准氢氧化钠溶液的当量浓度f:标准氢氧化钠溶液的溶液系数m:硫酸试样的质量:每毫升当量硫酸的质量二、灼烧残渣的测定1、仪器与设备蒸发皿50cc 沙浴加热器高温炉分析天平2、测定方法在分析天平上用减量法精确秤取20克左右(7-8管)的硫酸试样于恒重的瓷蒸发皿中,将瓷蒸发皿放在沙浴上,在通风橱中加热,蒸发干涸后移入高温炉调温至800℃时灼烧灰化4h,取出在干燥器中冷却30分钟后,称重。
3、计算灼烧残渣%=(M2-M1)*100/M试中:M1:试样瓷蒸发皿恒重质量M2:瓷蒸发皿和残渣质量M:硫酸试样三、铁含量的测定1、方法原理利用硫氰酸与三价铁在酸性溶液中生成红色络合物(在酸性溶液中),在一定浓度范围内溶液颜色深浅与铁的含量成正比,用目视比色法进行比色从而计算出铁的含量。
2、仪器与试剂移液管5ml 烧杯100ml 比色管100ml 刻度吸管1ml 盐酸硝酸电炉分析天平10%硫氰酸钾铁标准溶液T=ml 微量滴定管5ml 容量瓶200ml3、测定方法精确秤取10克左右(管)试样于盛有150ml蒸馏水的200ml容量瓶中,冷却至20℃,稀释至刻度摇匀。
用移液管吸取稀释液5ml,置于100ml烧杯中,加入1ml浓盐酸和1ml浓硝酸,再加入适量的蒸馏水冲洗杯壁,在电炉上加热煮沸5分钟,取下冷却至室温,移入100ml比色管中,加入10ml10%硫氰酸钾显色后,用蒸馏水稀释至刻度,摇匀,同时做空白试验。
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
1、硫酸浓度测定1.1 方法提要以甲基红—次甲基兰为指示剂,用氢氧化钠标准滴定溶液中和滴定以测得硫酸含量。
1.2 试剂和材料1.2.1 氢氧化钠标准滴定溶液:C(NaOH)=0.5 mol/L 1.2.2 甲基红—次甲基兰混合指示剂1.3 分析步骤1.3.1 用一称量的带有磨口的小称量瓶,称取约0.7g浓硫酸试样或1.5g左右50%硫酸试样(精确至0.0001g),小心移入盛有50mL水的250ml锥形瓶中,冷却至室温,备用。
1.3.2 试液中,加2—3滴混合指示剂(1.2.2),用氢氧化钠标准滴定溶液(1.2.1)滴定至溶液呈灰绿色为终点。
1.4 分析结果的表述硫酸的质量分数W1=C*V*(M/1000)*100/m=4.904*C*V/m 式中:V:滴定耗用的氢氧化钠标准滴定溶液的体积的数值,mL;C:氢氧化钠溶液的实际浓度的数值,mol/L;m:试料的质量的数值,g;M:硫酸的摩尔质量的数值,g/mol(M=49.04)2、灰分2.1 方法提要试料蒸发至干,灼烧,冷却后称量。
2.2 仪器、设备2.2.1 铂皿(或石英皿,瓷皿);容量60mL—100mL。
2.2.2 高温电炉:可控制温度(800±50)℃。
2.3 分析步骤将铂皿(2.2.1)于高温电炉(2.2.2)内,在800℃±50℃温度下灼烧15min,置于干燥器中,冷却至室温称量,精确至0.0001g。
称取约25g—20g试样于铂皿中(精确至0.01g),在可调温电炉或沙浴上,小心加热蒸发至干,移入高温电炉(2.2.2)内,在800℃±50℃温度下灼烧15min,取出铂皿,置于干燥器中,冷却至室温后称量,精确至0.0001g。
2.4 分析结果的表述硫酸灰分的质量分数W2(%)按下式计算: W2=m*100/m0式中:m:灼烧后灰分的质量的数值,g;m0:试料的质量的数值,g。
3、氯化物3.1 方法提要试样用水稀释,加硝酸及硝酸银与氯离子反应生成氯化银浑浊液,与标准色阶比较,求算出氯含量。
3.2 试剂和材料3.2.1 无氯硫酸:将硫酸(GB/T 625)加热至冒白烟赶Cl﹣后使用。
3.2.2 硝酸(GB/T 626)溶液:1+2。
3.2.3 硝酸银(GB/T 670)溶液:C(AgNO3)=0.1mol/L;3.2.4 氯标准溶液:1mL含氯0.100mg;3.2.5 氯标准溶液:1mL含氯0.010mg;用氯标准溶液( 3.2.4)稀释而得,该溶液使用时配制。
3.2.6 具塞玻璃比色管,容积50mL。
3.3 分析步骤称取约5g试样(精确至0.1g),在冷却条件下加入盛有25mL水的烧杯中,冷却后移入比色管中,加1mL硝酸溶液(3.2.2),2mL硝酸银(3.2.3),加水稀释至刻度,摇匀。
于暗处静置20min。
按上述操作,用无氯硫酸(3.2.1)代替试样制备标准色阶,依次含氯0.020、0.040、0.060、0.080 mg。
用目视比浊法确定氯含量。
3.4 分析结果的表述硫酸中氯的质量分数W3(%),按下式计算: W3=m*10﹣3*100/m0 式中:m:与试料浊度相当的标准色阶中氯(Cl)的质量的数值,mg;m0:试料试样的质量的数值,g。
4、铁含量的测定(邻菲啰啉分光光度法)4.1 方法提要试料蒸干后,残渣溶解于盐酸中,用盐酸羟胺还原溶液中的铁,在PH为2—9条件下,二价铁离子与邻菲啰啉反应生成橙色络合物,对此络合物作吸光度测试。
4.2 试剂和材料4.2.1 盐酸溶液:1+10。
4.2.2 盐酸羟胺溶液:10g/L。
4.2.3 乙酸—乙酸钠缓冲溶液:PH≈ 4.5。
4.2.4 邻菲啰啉盐酸溶液:1g/L。
4.2.5 铁标准溶液:0.100 mg/mL。
4.2.6 铁标准溶液:0.010 mg/mL。
4.2.7 分光光度计。
4.3 分析步骤4.3.1 试料溶液的制备称取10g—20g试样(精确至0.01g),置于50ml烧杯中,在可调温电炉上蒸发至干,冷却,加2ml盐酸溶液(4.2.1),和25ml水,加热使其溶解,移入100mL容量瓶中,用水稀释至刻度,摇匀,备用。
4.3.2 工作曲线的制作4.3.2.1 标准显色溶液的制备取6个50ml容量瓶,按表1所示,分别加入铁标准溶液(4.2.6)表 1 铁标准溶液体积 mL 对应铁质量 ug 0a 02.0 204.0 406.0 608.0 8010.0 100a 空白溶液对每一容量瓶中的溶液作下述处理:加水至25mL,加2.5mL盐酸羟胺溶液(4.2.2)和5mL 缓冲溶液(4.2.3),5min后加5mL邻菲啰啉溶液(4.2.4),用水稀释至刻度,摇匀,放置15min显色。
4.3.2.2 吸光度的测量在510nm波长处,用1cm吸收池,以水为参比,将分光光度计的吸光度调整到零后,测出标准显色溶液( 4.3.2.1)的吸光度。
4.3.2.3 工作曲线的绘制从每一标准显色溶液的吸收度值,减去空白溶液的吸光度值(4.3.2.2),以所得吸光度值差为纵坐标,对应的铁质量为横坐标绘制工作曲线。
4.3.3 试料的测定4.3.3.1 显色取一定量的试液(4.3.1),置于50mL容量瓶中,加水至约25mL,然后按4.3.2.1中说述“加 2.5mL盐酸羟胺溶液( 4.2.2)……”的步骤进行。
4.3.3.2 吸光度的测量按 4.3.2.2步骤,以水为参比,测量试液(4.3.3.1)的吸光度。
4.3.4 空白实验在测定试液(4.3.3.1)的同时,用同样的步骤,同样数量的试剂,不加试液作白色实验。
4.4 分析结果的表述从试液的吸光度值(4.3.3.2)减去空白实验的吸光度值(4.3.4),据所得吸光度值差从工作曲线(4.3.2.3)查出对应的铁质量,并按试液吸取比例计算出试样中的铁质量。
硫酸中铁的质量分数W4(%)按下式计算: W4=m*100/m0式中:m:试料中铁含量的质量的数值,g;m0:试料的质量的数值,g。
1、硫酸浓度测定1.1 方法提要以甲基红—次甲基兰为指示剂,用氢氧化钠标准滴定溶液中和滴定以测得硫酸含量。
1.2 试剂和材料1.2.1 氢氧化钠标准滴定溶液:C(NaOH)=0.5 molL1.2.2 甲基红—次甲基兰混合指示剂1.3 分析步骤1.3.1 用一称量的带有磨口的小称量瓶,称取约0.7g浓硫酸试样或1.5g左右50%硫酸试样(精确至0.0001g),小心移入盛有50mL水的250ml锥形瓶中,冷却至室温,备用。
1.3.2 试液中,加2—3滴混合指示剂(1.2.2),用氢氧化钠标准滴定溶液(1.2.1)滴定至溶液呈灰绿色为终点。
1.4 分析结果的表述硫酸的质量分数W1=CV(M1000)100m=4.904CVm式中:V:滴定耗用的氢氧化钠标准滴定溶液的体积的数值,mL;C:氢氧化钠溶液的实际浓度的数值,molL;m:试料的质量的数值,g;M:硫酸的摩尔质量的数值,gmol(M=49.04)2、灰分2.1 方法提要试料蒸发至干,灼烧,冷却后称量。
2.2 仪器、设备2.2.1 铂皿(或石英皿,瓷皿);容量60mL—100mL。
2.2.2 高温电炉:可控制温度(800±50)℃。
2.3 分析步骤将铂皿(2.2.1)于高温电炉(2.2.2)内,在800℃±50℃温度下灼烧15min,置于干燥器中,冷却至室温称量,精确至0.0001g。
称取约25g—20g试样于铂皿中(精确至0.01g),在可调温电炉或沙浴上,小心加热蒸发至干,移入高温电炉(2.2.2)内,在800℃±50℃温度下灼烧15min,取出铂皿,置于干燥器中,冷却至室温后称量,精确至0.0001g。
2.4 分析结果的表述硫酸灰分的质量分数W2(%)按下式计算:W2=m100m0式中:m:灼烧后灰分的质量的数值,g;m0:试料的质量的数值,g。
3、氯化物3.1 方法提要试样用水稀释,加硝酸及硝酸银与氯离子反应生成氯化银浑浊液,与标准色阶比较,求算出氯含量。
3.2 试剂和材料3.2.1 无氯硫酸:将硫酸(GBT 625)加热至冒白烟赶Cl﹣后使用。
3.2.2 硝酸(GBT 626)溶液:1+2。
3.2.3 硝酸银(GBT 670)溶液:C(AgNO3)=0.1molL;3.2.4 氯标准溶液:1mL含氯0.100mg;3.2.5 氯标准溶液:1mL含氯0.010mg;用氯标准溶液(3.2.4)稀释而得,该溶液使用时配制。
3.2.6 具塞玻璃比色管,容积50mL。
3.3 分析步骤称取约5g试样(精确至0.1g),在冷却条件下加入盛有25mL水的烧杯中,冷却后移入比色管中,加1mL硝酸溶液(3.2.2),2mL硝酸银(3.2.3),加水稀释至刻度,摇匀。
于暗处静置20min。
按上述操作,用无氯硫酸(3.2.1)代替试样制备标准色阶,依次含氯0.020、0.040、0.060、0.080 mg。
用目视比浊法确定氯含量。
3.4 分析结果的表述硫酸中氯的质量分数W3(%),按下式计算:W3=m10﹣3100m0式中:m:与试料浊度相当的标准色阶中氯(Cl)的质量的数值,mg;m0:试料试样的质量的数值,g。
4、铁含量的测定(邻菲啰啉分光光度法)4.1 方法提要试料蒸干后,残渣溶解于盐酸中,用盐酸羟胺还原溶液中的铁,在PH为2—9条件下,二价铁离子与邻菲啰啉反应生成橙色络合物,对此络合物作吸光度测试。
4.2 试剂和材料4.2.1 盐酸溶液:1+10。
4.2.2 盐酸羟胺溶液:10gL。
4.2.3 乙酸—乙酸钠缓冲溶液:PH≈4.5。
4.2.4 邻菲啰啉盐酸溶液:1gL。
4.2.5 铁标准溶液:0.100 mgmL。
4.2.6 铁标准溶液:0.010 mgmL。
4.2.7 分光光度计。
4.3 分析步骤4.3.1 试料溶液的制备称取10g—20g试样(精确至0.01g),置于50ml烧杯中,在可调温电炉上蒸发至干,冷却,加2ml盐酸溶液(4.2.1),和25ml水,加热使其溶解,移入100mL容量瓶中,用水稀释至刻度,摇匀,备用。
4.3.2 工作曲线的制作4.3.2.1 标准显色溶液的制备取6个50ml容量瓶,按表1所示,分别加入铁标准溶液(4.2.6)表1铁标准溶液体积 mL 对应铁质量 ug0a 02.0 204.0 406.0 608.0 8010.0 100a 空白溶液对每一容量瓶中的溶液作下述处理:加水至25mL,加2.5mL盐酸羟胺溶液(4.2.2)和5mL 缓冲溶液(4.2.3),5min后加5mL邻菲啰啉溶液(4.2.4),用水稀释至刻度,摇匀,放置15min显色。
4.3.2.2 吸光度的测量在510nm波长处,用1cm吸收池,以水为参比,将分光光度计的吸光度调整到零后,测出标准显色溶液(4.3.2.1)的吸光度。