阅读说明：本技术 一种利用表面活性剂强化浸取钾长石中钾的方法 (Method for strengthening leaching of potassium in potassium feldspar by using surfactant ) 是由 杨帆 马家玉 隋岩峰 汪铁林 王存文 覃远航 于 2021-01-21 设计创作，主要内容包括：本发明涉及一种利用表面活性剂强化浸取钾长石中钾的方法,其特征在于：包括以下步骤：(1)配料：将研磨后的钾长石、氟化物、表面活性剂与盐酸进行混合配料；(2)酸浸：将配好的料液在70-120℃下进行浸出反应,2-10小时后固液分离,得到一次滤渣和一次滤液；(3)二次过滤：将一次滤渣用热水洗涤后进行二次过滤,得到二次滤渣和二次滤液；(4)滤液混合：将一次滤液与二次滤液混合得到含钾的浸出液。本发明的有益效果是：与未添加表面活性剂相比,可以提高钾的浸出率5-20%,同时可以降低氟化物及盐酸的添加量。本发明不但可以用来处理钾长石,还可以用来处理粘土、霞石等多种含钾矿石。(The invention relates to a method for strengthening leaching of potassium in potassium feldspar by using a surfactant, which is characterized by comprising the following steps of: the method comprises the following steps: (1) preparing materials: mixing ground potassium feldspar, fluoride, a surfactant and hydrochloric acid; (2) acid leaching: leaching the prepared feed liquid at 70-120 ℃, and performing solid-liquid separation after 2-10 hours to obtain primary filter residue and primary filtrate; (3) secondary filtration: washing the primary filter residue with hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate; (4) mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate. The invention has the beneficial effects that: compared with the method without adding the surfactant, the leaching rate of potassium can be improved by 5-20%, and the addition amount of fluoride and hydrochloric acid can be reduced. The invention can be used for treating potassium feldspar, and can also be used for treating various potassium-containing ores such as clay, nepheline and the like.)

1. A method for strengthening leaching potassium in potassium feldspar by using a surfactant is characterized by comprising the following steps: the method comprises the following steps:

(1) preparing materials: mixing ground potassium feldspar, fluoride, a surfactant and hydrochloric acid;

(2) acid leaching: leaching the prepared feed liquid at 70-120 ℃, and performing solid-liquid separation after 2-10 hours to obtain primary filter residue and primary filtrate;

(3) secondary filtration: washing the primary filter residue with hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate;

(4) mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate.

2. The method for strengthening the leaching of the potassium in the potassium feldspar by using the surfactant as claimed in claim 1, wherein the method comprises the following steps: the fluoride in the step (1) is one or a mixture of more of calcium fluoride, magnesium fluoride, potassium fluoride, sodium fluoride, fluosilicic acid and potassium fluosilicate, and the addition amount of the fluoride is 1-20% of the weight of the potassium feldspar.

3. The method for strengthening the leaching of the potassium in the potassium feldspar by using the surfactant as claimed in claim 1, wherein the method comprises the following steps: the concentration of the hydrochloric acid used in the step (1) is 10-37%, and the dosage is liquid-solid ratio: the volume (mL) of the hydrochloric acid is 2: 1-6: 1 of potassium feldspar (g).

4. The method for strengthening the leaching of the potassium in the potassium feldspar by using the surfactant as claimed in claim 1, wherein the method comprises the following steps: the surfactant in the step (1) is one or a mixture of more of Sodium Dodecyl Benzene Sulfonate (SDBS), sodium oleate, Sodium Dodecyl Sulfate (SDS), glyceryl trioleate, polyvinyl alcohol (PVA), polyethylene glycol (6000, PEG), cetyl trimethyl ammonium bromide (CTMAB), Cetyl Pyridine Bromide (CPB) and hexamethylene tetramine, and the addition amount of the surfactant is 0.5-5 g/L.

Technical Field

The invention relates to the field of inorganic chemical industry, in particular to a method for strengthening leaching potassium in potassium feldspar by using a surfactant.

Background

The potash fertilizer is used as nutrient element fertilizer for crops and plays an extremely important role in the life metabolic process of the crops. But in China, the yield and the dosage of the potassium fertilizer and the compound fertilizer thereof are insufficient. The extraction of potassium is mainly from soluble potassium salt deposit, but is seriously deficient in China. According to statistics, the reserves of the water-soluble sylvite in the world of 2012 are 95.52 hundred million tons in K2O, 2.1 million tons in China account for about 2.2 percent of the total reserves in the world, are mainly distributed in the Qinghai Kerr sweat lake and the Xinjiang Apocynum venetum lake, and are not convenient to develop and utilize. The water-insoluble potassium-containing ore beds in China are abundant, the reserves exceed 200 hundred million tons, and the potassium feldspar is mostly distributed in middle and eastern agriculture developed areas in the form of potassium feldspar. Therefore, it has become an urgent necessity to efficiently and economically extract soluble potassium from water-insoluble potassium-containing deposits such as potassium feldspar.

The potassium feldspar has a stable tetrahedral structure, is difficult to decompose by common acid and alkali, and the existing methods for extracting potassium from the potassium feldspar at home and abroad mainly comprise a high-temperature volatilization method, a high-temperature sintering method, a hydrothermal method, a microbial decomposition method, a low-temperature acid leaching method and the like. The high-temperature volatilization method is to mix potassium feldspar, limestone, dolomite, fluorite and coke according to a certain proportion and carry out high-temperature reaction to volatilize K₂O and CO in furnace₂ Generation of K₂CO₃However, the method has high energy consumption and low potassium recovery rate. The high-temperature sintering method is to mix potassium feldspar and additives and then melt and bake, and the method also has high energy consumption and is difficult to process after sintering. The hydrothermal method is to react potassium feldspar, an additive and alkali under the hydrothermal condition, and compared with a high-temperature sintering method, the energy consumption of the hydrothermal method is reduced, but the leaching rate of potassium is low (<85%), a large amount of residue (e.g., calcium aluminosilicate) obtained by the reaction, and difficulty in large-scale utilization. The microbial decomposition method is to carry out biochemical reaction between metabolites such as microbial bacteria and the like and potassium feldspar, has simple process and no three-waste discharge problem, but has the defects of low potassium recovery rate, difficult strain breeding, large domestication difficulty and the like. The low-temperature acid leaching method is to decompose potassium feldspar by using a fluorine-containing auxiliary agent under inorganic acid, has the advantages of low leaching temperature, high potassium leaching rate, convenience for subsequent treatment and the like although the method has high requirements on the corrosion resistance of equipment, and is gradually concerned by researchers.

The applicant treats the potassium feldspar with hydrochloric acid in the earlier stage, and the potassium leaching rate is up to more than 90% under the optimized process conditions. But still has the problems of large acid dosage and additive dosage, overlong reaction time and the like, so the strengthening of the acid leaching process of the potassium feldspar is urgently needed. In recent years, the effects of emulsification, dispersion, wetting, penetration and the like of the surfactant have been effectively applied to the mineral leaching process. For example, the application of the surfactant in the leaching process of low-grade phosphorite, copper ore, zinc ore and other minerals is reported in the prior literature. However, the studies on the enhanced leaching of potassium feldspar by surfactants are extremely limited.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for strengthening and leaching potassium in potassium feldspar by using a surfactant, which is economic and environment-friendly and can efficiently leach the potassium in the potassium feldspar.

The purpose of the invention is realized by the following technical scheme:

a method for strengthening leaching of potassium in potassium feldspar by using a surfactant comprises the following steps:

(1) preparing materials: mixing the ground potassium feldspar, the fluoride, the surfactant and hydrochloric acid.

(2) Acid leaching: leaching the prepared feed liquid at 70-120 ℃, and carrying out solid-liquid separation after 2-10 hours to obtain primary filter residue and primary filtrate.

(3) Secondary filtration: and washing the primary filter residue with hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate.

(4) Mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate.

The fluoride in the step (1) is one or a mixture of more of calcium fluoride, magnesium fluoride, potassium fluoride, sodium fluoride, fluosilicic acid, potassium fluosilicate and the like, and the addition amount of the fluoride is 1-20% of the weight of the potassium feldspar.

The concentration of the hydrochloric acid used in the step (1) is 10-37%, and the dosage is 2: 1-6: 1 of liquid-solid ratio.

The surfactant in the step (1) is one or a mixture of more of Sodium Dodecyl Benzene Sulfonate (SDBS), sodium oleate, Sodium Dodecyl Sulfate (SDS), glyceryl trioleate, polyvinyl alcohol (PVA), polyethylene glycol (6000, PEG), cetyl trimethyl ammonium bromide (CTMAB), Cetyl Pyridine Bromide (CPB), hexamethylenetetramine and the like, and the addition amount of the surfactant is 0.5-5 g/L.

Since potassium feldspar has a stable structure and does not generally react with other acids except hydrofluoric acid, hydrofluoric acid or fluoride salt (such as calcium fluoride) and other acids (such as sulfuric acid, phosphoric acid and hydrochloric acid) are required to be added in the process of decomposing the potassium feldspar by acid. Due to the corrosiveness and the dangerousness of hydrofluoric acid, potassium feldspar is generally decomposed in a manner of reacting fluoride salt with acid to generate hydrofluoric acid in situ. The existing research shows that the hydrochloric acid has the highest extraction rate of potassium in the potassium feldspar, the sulfuric acid times are the lowest, and the phosphoric acid is the worst. The method adopts fluoride as an additive and hydrochloric acid as a leaching agent to treat the potassium feldspar, and relates to main chemical reactions including (additive CaF)₂For example):

CaF₂ + 2HCl = CaCl₂ + 2HF^↑ (1)

12HF + KAlSi₃O₈ + 4HCl = KCl + AlCl₃ + 3SiF₄ ^↑ + 8H₂O (2)

4HF + SiO₂ =SiF₄ ^↑+2H₂O (3)

2HF + SiF₄ = H₂SiF₆ (4)

3SiF₄ + 2H₂O = 2H₂SiF₆ + SiO₂↓(5)

H₂SiF₆ =2HF^↑+ SiF₄ ^↑ (6)

the results of the research show that: when CaF2 is used as an additive, the leaching rate of potassium element in the potassium feldspar is more than 90% at 90 ℃, but the dosage of hydrochloric acid and fluoride is large, the reaction time is too long, and the concentration of the pickle liquor is low, which causes difficulty in subsequent separation. The invention uses surfactant to strengthen the acid leaching process, and achieves the purposes of improving the reaction rate, shortening the reaction time and reducing the dosage of hydrochloric acid and fluoride.

Compared with the prior art, the invention has the advantages that:

(1) compared with the method without adding the surfactant, the method has the advantages of shortening the reaction time, reducing the consumption of hydrochloric acid and fluoride and improving the potassium leaching rate.

(2) The used surfactant has wide selection range and low addition amount.

(3) The process of the invention does not relate to high temperature and high pressure, and a plurality of production devices can refer to inorganic chemical industries such as wet-process phosphoric acid, soda chemical industry and the like, so the process of the invention is easy to implement.

(4) It can be used for treating potassium feldspar, and can also be used for treating various potassium-containing ores such as clay and nepheline.

Drawings

FIG. 1 is a schematic process flow diagram of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples, but the present invention is not limited thereto.

Example 1

(1) Preparing materials: 80g of ground potassium feldspar, 4g of calcium fluoride, 0.3g of SDS and 320mL of 22.5% hydrochloric acid solution are mixed and proportioned.

(2) Acid leaching: and (3) carrying out leaching reaction on the prepared feed liquid at 90 ℃, and carrying out solid-liquid separation after 4 hours to obtain primary filter residue and primary filtrate.

(3) Secondary filtration: and washing the primary filter residue with 100mL of hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate.

(4) Mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate.

The leaching rate of potassium element in the potassium feldspar is 92.5 percent through detection; if the surfactant is not added and the conditions are the same, the leaching rate of potassium is 81.5 percent, and if the leaching rate is more than 90 percent, the addition amount of calcium fluoride needs to be increased to 8 g.

Example 2

(1) Preparing materials: 80g of ground potassium feldspar, 4g of magnesium fluoride, 0.3g of SDBS and 160mL of 15% hydrochloric acid solution are mixed and proportioned.

(2) Acid leaching: and (3) carrying out leaching reaction on the prepared feed liquid at 70 ℃, and carrying out solid-liquid separation after 4 hours to obtain primary filter residue and primary filtrate.

(3) Secondary filtration: and washing the primary filter residue with 100mL of hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate.

(4) Mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate

The detection result shows that the leaching rate of the potassium is 78.5%.

Example 3

(1) Preparing materials: 80g of ground potassium feldspar, 8g of potassium fluosilicate, 0.5g of PVA and 480mL of 37% hydrochloric acid solution are mixed and proportioned.

(2) Acid leaching: and (3) carrying out leaching reaction on the prepared feed liquid at 120 ℃, and carrying out solid-liquid separation after 8 hours to obtain primary filter residue and primary filtrate.

(3) Secondary filtration: and washing the primary filter residue with 100mL of hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate.

(4) Mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate.

The detection result shows that the leaching rate of the potassium is 93.7 percent.

Example 4

(1) Preparing materials: 80g of ground potassium feldspar, 4g of fluosilicic acid, 1g of CTMAB and 320mL of 25% hydrochloric acid solution are mixed and proportioned.

(2) Acid leaching: and (3) carrying out leaching reaction on the prepared feed liquid at 100 ℃, and carrying out solid-liquid separation after 10 hours to obtain primary filter residue and primary filtrate.

(3) Secondary filtration: and washing the primary filter residue with 100mL of hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate.

(4) Mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate.

The detection result shows that the leaching rate of the potassium is 90.8%.

Example 5

(1) Preparing materials: 80g of ground potassium feldspar, 3g of fluosilicic acid and 2g of calcium fluoride, 1.5g of hexamethylenetetramine and 320mL of 25% hydrochloric acid solution are mixed and proportioned.

(2) Acid leaching: and (3) carrying out leaching reaction on the prepared feed liquid at 90 ℃, and carrying out solid-liquid separation after 8 hours to obtain primary filter residue and primary filtrate.

(3) Secondary filtration: and washing the primary filter residue with 100mL of hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate.

(4) Mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate.

The detection result shows that the leaching rate of the potassium is 94.8%.

Example 6

(1) Preparing materials: 80g of ground potassium feldspar, 6g of sodium fluoride, 0.5g of SDS + 0.5g of CPB and 320mL of 25% hydrochloric acid solution are mixed and proportioned.

(2) Acid leaching: and (3) carrying out leaching reaction on the prepared feed liquid at 90 ℃, and carrying out solid-liquid separation after 8 hours to obtain primary filter residue and primary filtrate.

(3) Secondary filtration: and washing the primary filter residue with 100mL of hot water, and then carrying out secondary filtration to obtain secondary filter residue and secondary filtrate.

(4) Mixing the filtrates: mixing the primary filtrate and the secondary filtrate to obtain potassium-containing leachate.

The detection result shows that the leaching rate of the potassium is 91.6%.