The Improvement Of Technology In The Production Of Copper Sulfate

The cupric sulfate products have two main problems in the cupric salt factory of Jinchuan Corporation.First,during the crystallization process,the factors of influencing the crystallization,namely stirring speed,stirring paddle form, temperature decrease gradient,were lack of further research and effective controls. Now,there were three problems about the product.First,the crystal granules were not homogeneous;the appearance was irregular.Second,the crystal was easy broken. Third,the crystal was easy dehydrated when dried.Second,during the extract procedure,because the high contents of arsenic(As) and calcium(Ca) in raw material are easy to form the calcium salt crystallization,they affect the normal rtm of the extract procedure and specially the quality of cupric sulfate product.This caused the contents of arsenic(As),calcium(Ca) in the products to be exceeded.So,the products did not measure up to the standards of Feed Grade Cupric Sulfate and Cupric Sulfate for Electroplating Use(the first-grade product and the superior product).According to the present productive craft and equipment conditions of Jinchuan Corporation cupric salt factory,this article studies and develops a method,which was easy to control and can achieve the technology targets.The studies were as following:(1) Crystallization operation:we have studied the various technological conditions. It's including the supersaturating degree of solution,the of concentration solution,the cooling rate and temperature of solution,the PH value of solution,the quantity and shape of the crystal,crystallization time,stirring speed,stirring paddle form and other correlation conditions.Then the best crystallization technological conditions were determined.The improved technological conditions of crystallization have some advantages, for example,simple operation,need not the specific installation,only make slight improvement on the original equipment.But the production cost cannot therefore enhance.The production consumption cannot therefore increase.Most of all,it has not any influence to the crystallization rate.Each time tests the cupric sulfate crystal can achieve crystal compactly,glitter and transparence.The first finished rate of products was above 80%which granularity was between 0.7～1.5mm;The cupric sulfate crystal which granularity is smaller than the 0.7mm is approximately 8%;The cupric sulfate crystal which the granularity is bigger than the 1.5mm is approximately 2%.(2) The operation of eliminating the arsenic:this test mainly uses the method of adding impurity eliminator.We have studied the followed parameters:the kinds and dosage of impurity eliminator,the beginning concentration of solution,solution concentration,pH value,the method and speed of filtration in order to determine the best eliminating technological conditions and the suitable impurity eliminator.We have found the high effective drugs and the best operation technological conditions. These drugs are common,easy.The price is inexpensive.The amount used was very micro.They couldn't introduce the new impure ion into the end product of cupric sulfate.The operation of technological conditions had been done easy,the steps were a few.The optimized eliminating technological conditions saved energy.The contents of arsenic decreased below the standard of all grade of cupric sulfate product with this method,and had achieved completely proposed request by the project.(3) The operation of eliminating the calcium:The original solution of cupric sulfate is an extremely complicated mixed system.The calcium ion was very stable.It is very difficult to not only reduce the loss of cupric sulfate product but also completely eliminating the calcium ion(≤0.0005%) because the highly concentrated cupric ion and calcium ion exist at the same time.The contents of calcium decreased below the standard of all grade of cupric sulfate product through a series of chemistries and physics,and had achieved completely proposed request by the project.Through the above two steps the operation,two grades of cupric sulfate products were obtains.First kind of grade:Feed grade cupric sulfate and first-grade cupric sulfate for electroplating use.The contents of arsenic(As) was 0.00002%and conformed to the HG2932-1999 standard,namely Arsenic(As)≤0.0004%;The second kind of grade:the superior grade cupric sulfate product for electroplating use. Arsenic(As):<0.00001%,calcium(Ca):0.00020%.It was conformed to the superior product standard(HG/T3592-1999),namely Calcium(Ca):≤0.0005%,arsenic(As):≤0.0005%.The expense of eliminating arsenic and calcium is 42.94 Yuan per cubic meter cupric sulfate before evaporation.There was not also any new impurity ingredient introduced into the product.