CN1122111C - Method for preparing high-purity zinc oxide by using smithsonite - Google Patents

Abstract

The present invention relates to a method for preparing zinc oxide with high purity of at least 99.7% from smithsonite, which is characterized in that the present invention adopts smithsonite stones as base materials and prepares zinc oxides with high purity of at least 99.7% by the steps: leaching H2 SO4, doping Zn powder for removing impurities to prepare zinc carbonate hydroxide and finally vaporizing at the high temperature of 1700 DEG C to 2000 DEG C.The recovery rate of zinc is 90%. The present invention has the advantages of simple manufacturing process, little investment, largely lowered cost, widened application range of raw materials, realized low cost production and possession of strong market competitiveness, and the quality of products is superior to the standard of GB/T3185-92.

Description

The method of preparing high-purity zinc oxide by using smithsonite

The present invention relates to a kind of method of producing height 〉=99.7% pure zinc oxide by smithsonite.

The method of the high-purity zinc oxide of China's production at present (content is 〉=99.7%) is to adopt 1 ^#Zinc ingot metal is a raw material, produces under 1000 ℃ of left and right sides temperature through indirect method, and this method production cost height adopts the ingredient requirement height, deficiency in economic performance, and the market competitiveness is low.

The objective of the invention is to overcome above-mentioned defective, the method by preparing high-purity zinc oxide by using smithsonite that a kind of raw material is wide, low-grade, production cost is low is provided.

Technical scheme of the present invention: the method by preparing high-purity zinc oxide by using smithsonite is that the low-grade smithsonite masonry of employing is a base-material, through H ₂SO ₄Leaching, removal of impurities transform produces zinc subcarbonate, obtains 〉=99.7% high pure zinc oxide through the high-temperature evaporation zinc subcarbonate again, and its concrete steps are as follows:

A, base-material screening are that low-grade smithsonite stone is pulverized, and screen as base-material through 120 eye mesh screens then;

B, employing concentration are the H of 60g/L～100g/L ₂SO ₄Solution mixes with screening base-material well, carries out the stirring reaction leaching in steel basin, and stirring leaching temperature is 80 ℃～90 ℃, refilters and obtains ZnSO ₄Solution, with the lime neutralization, its pH value is 4.5～5.2;

C, employing are mixed the method for Zn powder and are removed impurity, promptly at ZnSO ₄Mix Zn powder and CuSO in the solution ₄Stir, its whipping temp is 80 ℃～90 ℃, and the stirring reaction time is 1～2 hour, thereby removes Cu, Co and Ni impurity, mixes Zn powder and CuSO ₄Stir, whipping temp is 50 ℃～60 ℃, removes Cu and Cd impurity, and the time is 1 hour, mixes hydrogen peroxide at last and reacted 1 hour when temperature is 60 ℃, removes remaining manganese, iron contamination, and obtains ZnSO ₄Scavenging solution;

D, at ZnSO ₄Mix NH in the scavenging solution ₄HCO ₃To pH value be 7～8, i.e. ZnSO ₄Be converted into zinc subcarbonate;

E, zinc subcarbonate is placed the vaporization of heating in the High Temperature Furnaces Heating Apparatus, Heating temperature is 1700 ℃～2000 ℃, and zinc subcarbonate is 1700 ℃～2000 ℃ and high-temperature evaporation receives 〉=99.7% high-purity zinc oxide through the cooling bag collection again in temperature.

In sum, technology of the present invention is simple, less investment, reduced production cost, widen the raw material scope of application, non-environmental-pollution in process of production, through high-temperature evaporation method (1700 ℃～2000 ℃) but production purity is 〉=99.7% zinc oxide, quality product is better than the standard of GB/T3185-92, realized low cost production, the very strong market competitiveness has been arranged.

Below in conjunction with embodiment the present invention is further described.

Embodiment: as make 0.98 kilogram, content is that 〉=99.7% zinc oxide step is as follows:

1, getting 4.5 kilograms in the smithsonite stone that contains zinc 20%, through ball milling to 120 order, is the H of 60g/L with concentration ₂SO ₄Solution 28L, temperature are 85 ℃～90 ℃, put into steel basin and stir leaching 1 hour, filter and obtain ZnSO ₄Solution, being neutralized to pH value with lime is 5.

2, removal of impurities divides three steps to carry out, and the first step adds Zn powder and CuSO respectively ₄Each 15 gram, temperature of reaction is controlled to be 85 ℃～90 ℃, and stirring reaction 1.5 hours can be removed Cu, Co, Ni impurity; Second step was got Zn powder and CuSO again ₄Each 5 gram adds ZnSO ₄In the solution, temperature of reaction is controlled at 50 ℃～55 ℃, can remove Cu, Cd impurity; The 3rd step added hydrogen peroxide 10 grams, and temperature of reaction is 60 ℃, reacts 1 hour, removes remaining Mn, Fe, obtains ZnSO ₄Scavenging solution.

3, at ZnSO ₄Add NH in the scavenging solution ₄HCO ₃To pH value be 7.5, i.e. ZnSO ₄Be converted into zinc subcarbonate.

4, with zinc subcarbonate in High Temperature Furnaces Heating Apparatus internal heating to 1700 ℃～2000 ℃ of vaporizations, obtain 0.98 kilogram through the cooling bag collection, content is 〉=99.7% zinc oxide, its quality is better than (GB/T3185-92) standard.

Claims (1)

1, by the method for preparing high-purity zinc oxide by using smithsonite, it is characterized in that adopting low-grade smithsonite masonry is base-material, through H ₂SO ₄Zinc subcarbonate is produced in leaching, removal of impurities, obtains 〉=99.7% high-purity zinc oxide through the high-temperature evaporation zinc subcarbonate again, and its concrete steps are as follows:

A, base-material screening are that low-grade smithsonite stone is pulverized, and screen as base-material through 120 eye mesh screens then;

B, employing concentration are the H of 60g/L～100g/L ₂SO ₄Solution mixes with screening base-material well, carries out the stirring reaction leaching in steel basin, and stirring leaching temperature is 80 ℃～90 ℃, refilters and obtains ZnSO ₄Solution, with the lime neutralization, its pH value is 4.5～5.2;

C, employing are mixed the method for Zn powder and are removed impurity, promptly at ZnSO ₄Mix Zn powder and CuSO in the solution ₄Stir, its whipping temp is 80 ℃～90 ℃, and the stirring reaction time is 1～2 hour, thereby removes Cu, Co and Ni, mixes Zn powder and CuSO again ₄Stir, whipping temp is 50 ℃～60 ℃, removes Cu and Cd, and the time is 1 hour, mixes hydrogen peroxide at last and reacted 1 hour when temperature is 60 ℃, removes remaining manganese, iron contamination, and obtains ZnSO ₄Scavenging solution.

D, at ZnSO ₄Mix NH in the scavenging solution ₄HCO ₃To pH value be 7～8, i.e. ZnSO ₄Be converted into zinc subcarbonate;

E, zinc subcarbonate placed heat vaporization in the High Temperature Furnaces Heating Apparatus, Heating temperature is 1700 ℃～2000 ℃, and zinc subcarbonate is 1700 ℃～2000 ℃ and high-temperature evaporation receives 〉=99.7% high-purity zinc oxide through the cooling bag collection again in temperature.