阅读说明：本技术 一种一水硫酸锌的生产方法 (Production method of zinc sulfate monohydrate ) 是由 刘珍宝 于 2019-11-27 设计创作，主要内容包括：本发明属于化工生产制备领域,具体是涉及到一种一水硫酸锌的生产方法,包括如下步骤,1)将原料氧化锌用温度为90-100℃的热水进行洗涤,然后加入到硫酸溶液中,反应,过滤,得到初级滤液；2)在初级滤液中先后加入双氧水和氢氧化锌,反应,除去铁杂质和多余的硫酸,过滤,得到次级滤液；3)在次级滤液中加入锌粉,进行置换反应,过滤,得到过滤液；4)对过滤液进行加热,加热温度为70-90℃,同时在过滤液中通入70-90℃的纯净空气,控制空气流量为0.1-0.5m<Sup>3</Sup>/h,使过滤液蒸发结晶,然后将结晶物进行微波干燥,得到一水硫酸锌；本发明产品质量稳定性更高,不易结块。(The invention belongs to the field of chemical production and preparation, and particularly relates to a production method of zinc sulfate monohydrate, which comprises the following steps of 1) washing raw material zinc oxide by hot water with the temperature of 90-100 ℃, then adding the raw material zinc oxide into sulfuric acid solution, reacting, and filtering to obtain primary filtrate; 2) adding hydrogen peroxide and zinc hydroxide into the primary filtrate in sequence, reacting, removing iron impurities and redundant sulfuric acid, and filtering to obtain secondary filtrate; 3) adding zinc powder into the secondary filtrate, performing a displacement reaction, and filtering to obtain filtrate; 4) heating the filtrate at 70-90 deg.C, introducing 70-90 deg.C purified air, and controlling air flow at 0.1-0.5m 3 Evaporating and crystallizing the filtrate, and then carrying out microwave drying on a crystal to obtain zinc sulfate monohydrate; the product has higher quality stability and is not easy to agglomerate.)

1. A production method of zinc sulfate monohydrate is characterized by comprising the following steps,

1) washing raw material zinc oxide with hot water at the temperature of 90-100 ℃, then adding the raw material zinc oxide into sulfuric acid solution, reacting, and filtering to obtain primary filtrate;

2) adding hydrogen peroxide and zinc hydroxide into the primary filtrate in sequence, reacting, removing iron impurities and redundant sulfuric acid, and filtering to obtain secondary filtrate;

3) adding zinc powder into the secondary filtrate, performing a displacement reaction, and filtering to obtain filtrate;

4) heating the filtrate at 70-90 deg.C, introducing 70-90 deg.C purified air, and controlling air flow at 0.1-0.5m³And h, evaporating and crystallizing the filtrate, and then drying crystals by microwave to obtain the zinc sulfate monohydrate.

2. The method for producing zinc sulfate monohydrate as claimed in claim 1, wherein said sulfuric acid solution is a 60-80% by weight sulfuric acid solution.

3. The method for producing zinc sulfate monohydrate as claimed in claim 1, wherein the weight of the hydrogen peroxide is 2-3% of the weight of the primary filtrate.

4. A process as claimed in any one of claims 1 to 3, wherein the weight of zinc hydroxide is from 1 to 2% of the weight of the primary filtrate.

5. A process as claimed in any one of claims 1 to 3, wherein the zinc powder is present in an amount of 1 to 2% by weight of the secondary filtrate.

6. A process for the production of zinc sulphate monohydrate as claimed in any one of claims 1 to 3 and characterised by controlling the air flow rate to between 0.1 and 0.2m³/h。

7. The method for producing zinc sulfate monohydrate as claimed in any one of claims 1 to 3, wherein said microwave drying is carried out by drying the crystal under a microwave having a frequency of 915 MHz for 5 to 10 minutes.

Technical Field

The invention belongs to the field of chemical production and preparation, and particularly relates to a production method of zinc sulfate monohydrate.

Background

The zinc sulfate monohydrate is white flowable powder with the density of 3.28g/cm³Soluble in water, slightly soluble in alcohol, very deliquescent in air, and insoluble in acetone. It is generally prepared by reacting zinc oxide or hydroxide with sulfuric acid. The zinc salt is mainly used as a production raw material of other zinc salts, and is used for preparing pure zinc by cable galvanizing and electrolysis, a spraying agent for fruit tree nursery diseases, and a preservative for artificial fibers, wood and leather.

The production process of zinc sulfate mainly comprises the following steps: 1. the synthesis method of zinc salt or zinc oxide and sulfuric acid comprises 2, sulfuric acid leaching zinc ore, 3, calcining zinc blende and the like.

The production flow of producing the zinc sulfate monohydrate by using the zinc oxide generally comprises the following steps: rinsing zinc oxide → zinc oxide + sulfuric acid → middle leaching reaction → rough filtration → adding hydrogen peroxide + deironing → adding zinc oxide, adjusting pH value → filter pressing → adding zinc powder, removing cadmium → filter pressing → multiple-effect evaporation → concentrated crystallization → centrifugal dehydration → drying → packaging.

When enterprises produce, the quality of certain batches of products is unstable due to the instability of raw materials, which is mainly shown in that:

1. after the zinc sulfate solution of a certain batch is concentrated, the dehydration is difficult, and the dehydration is difficult even if the zinc sulfate solution is dried by a rotary kiln. The reason for this may be that the crystal size is too fine, or the crystal nuclei grow slowly, or the raw material contains a large amount of impurities, resulting in a problem in crystal morphology.

2. The zinc sulphate product has the problem of caking, and the possible reasons are that:

1) the raw materials have more impurities during production, so that the product contains more impurities, and the impurities are easy to absorb moisture, so that the product absorbs water and is easy to agglomerate;

2) the produced zinc sulfate is very high in temperature, and is filled into bags too early due to goods driving or site reasons, so that the temperature in the packaging bags is too high, and the zinc sulfate is caked due to the fact that the zinc sulfate is not ventilated or is high in temperature in the long-distance transportation process.

The Chinese patent application No. 201710445558.4 discloses a preparation method of high-purity zinc sulfate monohydrate, which specifically comprises the following steps: step 1, adding a zinc sulfate solution and a pH value adjusting solution into a reaction kettle for reaction, performing filter pressing separation after the reaction is finished to obtain filter residues, and pulping the filter residues by using the zinc sulfate solution to obtain Zn-containing slurry; step 2, adding the zinc sulfate solution into a callback kettle, using the Zn-containing slurry prepared in the step 1 to callback the pH value of the zinc sulfate solution, and filtering and separating the solution with the pH value being recalled to obtain zinc sulfate filtrate; step 3, evaporating and concentrating the zinc sulfate filtrate obtained in the step 2 to obtain a concentrated material; and 4, centrifugally separating the concentrated material, heating and sieving to obtain zinc sulfate monohydrate powder. This scheme is through adding zinc sulfate and adjusting pH value repeatedly to remove the impurity and improve crystallization solution concentration, but this kind of operation is difficult to solve above-mentioned problem.

Disclosure of Invention

The invention aims to solve the technical problem of providing a production method of zinc sulfate monohydrate, which has higher product quality stability and is not easy to agglomerate.

The invention relates to a method for producing zinc sulfate monohydrate, which comprises the following steps,

1) washing raw material zinc oxide with hot water at the temperature of 90-100 ℃, then adding the raw material zinc oxide into sulfuric acid solution, reacting, and filtering to obtain primary filtrate;

2) adding hydrogen peroxide and zinc hydroxide into the primary filtrate in sequence, reacting, removing iron impurities and redundant sulfuric acid, and filtering to obtain secondary filtrate;

3) adding zinc powder into the secondary filtrate, performing a displacement reaction, and filtering to obtain filtrate;

4) heating the filtrate at 70-90 deg.C, introducing 70-90 deg.C purified air, and controlling air flow at 0.1-0.5m³And h, evaporating and crystallizing the filtrate, and then drying crystals by microwave to obtain the zinc sulfate monohydrate.

The sulfuric acid solution is 60-80% by weight.

The weight of the hydrogen peroxide is 2-3% of the weight of the primary filtrate.

The weight of the zinc hydroxide is 1-2% of the weight of the primary filtrate.

The weight of the zinc powder is 1-2% of the weight of the secondary filtrate.

Controlling air flow rate to 0.1-0.2m³/h。

The microwave drying method comprises drying the crystal under 915 MHz microwave for 5-10 min.

The method has the advantages that the raw materials are washed in hot water at the temperature close to 100 ℃, the chlorine content in the hot water is low, the possibility of additionally bringing chloride ions can be avoided, and meanwhile, the raw materials are heated, so that when the raw materials react with sulfuric acid, on one hand, the temperature is high, the reaction speed is high, and on the other hand, the subsequent impurity removal is facilitated.

When the evaporation crystallization is carried out, on one hand, the filtrate is heated, on the other hand, a small amount of pure air is introduced into the filtrate, the flow rate of the air is low, the growth of crystals is influenced by the air when the filtrate is subjected to the evaporation crystallization, the particle size of the crystals is proper and not large or small, and therefore the problems of subsequent drying and storage are well solved.

Detailed Description