干法氟化铝生产简介

2009 届毕业设计(论文) 课题名称：干法氟化铝生产简介

系、部：材料与化学工程系

学生姓名：林兰

指导教师：李昶红

职称：副教授

专业：应用化工技术

班级：应化0601班

学号： 702060109

2009年5月

摘要

氟化铝(AlF3) 是铝电解生产过程中的一种主要辅助材料（主要用作于铝电解的助熔剂，用于调整电解槽电解质的分子比水平），其含水量对电解铝生产和净化过程影响很大。

中国是二十世纪九十年代引进瑞士Buss干法工艺，并建成了无水氟化铝生产线。无水氟化铝具有主含量高、水分低、堆积比重大的特点，特别适用于电解槽启动后降低电解质分子比。与湿法产品相比，无水氟化铝在使用中有以下优点：a、主含量在90%以上，高出湿法产品近5个百分点，杂质含量低，节约了氟化铝用量，降低了生产成本，有利于提高原铝质量。b、水分含量低，小于1.0%，远远低于湿法产品水分7.0%的水平，在电解过程中使用无水氟化铝产品，AlF3几乎不发生水解反应，其可利用的有效成份远远高于湿法产品。更为主要的是避免了使用湿法产品因氟化铝的水解造成的操作环境恶劣的状况，有利于环境保护。总之，干法工艺流程短，工艺紧凑；原料消耗低；环境污染少，产品质量好等。本文主要介绍氟化氢—无水工艺法制备干法氟化铝工艺及控制方案。干法氟化铝按工艺流程分为氟化氢制备（包括酸给料、萤石给料、氟化氢反应炉）及氟化铝制备包括流化床、尾气处理、成品处理。流程如下：1.萤石(CaF2)粉料与浓硫酸(98%)及发烟硫酸(104.5%)的混合物在反应炉里反应生成HF气体与石膏(CaSO4)。2.HF气体经净化后在流化床内与干燥的Al(OH)3反应生成AlF3, AlF3经冷却后送至成品库，尾气经中央吸收处理后放空。

关键词：干法工艺;萤石；氟化铝;反应炉；氟化铝反应器；中央吸收

Abstract

The aluminum fluoride (AlF3) is in the aluminum electrolysis production process one main accessory material (mainly serves as in aluminum electrolysis flux, uses in adjusting electric tank electrolyte molecular proportion level), its water content is very big to the electrolytic aluminium production and the purification process influence. the China was the 1990s introduces the Swiss Buss dry process craft, and has completed the anhydrous aluminum fluoride production line. The anhydrous aluminum fluoride has the main content to be high, the moisture content is low, the stack proportion major characteristic, is suitable specially starts after the electric tank reduces the electrolyte molecular proportion. Compares with the aqueous method product, the anhydrous aluminum fluoride has the following merit in the use: a, the host content above 90%, was higher than the aqueous method product nearly 5 percentage points, the foreign inclusion is low, saved the aluminum fluoride amount used, reduced the production cost, was advantageous in raises the plateau aluminum quality. b, the moisture content is low, is smaller than 1.0%, is lower than the aqueous method product moisture content 7.0% levels by far, uses the anhydrous aluminum fluoride product in the electrolysis process, AlF3 does not have the hydrolitic reaction nearly, its may the use active principle be higher than the aqueous method product by far. What is more main has avoided the operating environment bad condition which because the use aqueous method product the aluminum fluoride hydrolisis created, was advantageous in the environmental protection. In brief, the

dry process technical process is short, the craft is compact; The consumption of material is low; The environmental pollution are few, product quality good and so on. This article main introduction hydrogen fluoride - anhydrous craft law preparation dry process aluminum fluoride craft and control plan. The dry process aluminum fluoride divides into the hydrogen fluoride preparation according to the technical process (including acid to material, fluorspar to give material, hydrogen fluoride reactor) and the aluminum fluoride preparation including the fluid bed, exhaust processing, end product processing. The flow is as follows: 1. the fluorspar (CaF2) powder lot and the strong sulfuric acid (98%) and the fuming sulfuric acid (104.5%) mixture in the reactor responded that produces the HF gas and the gypsum (CaSO4). 2.HF gas after purification in the fluid bed produces AlF3 with the dry Al(OH)3response, AlF3after cooling songzhi the stock, the exhaust after central absorption processing blows off.

key word: Dry process craft; Fluorspar; Aluminum fluoride; Reactor; Fluid bed; The central committee absorbs