CN-121974467-A - Preparation method of high-concentration fluorine-containing wastewater remover

CN121974467ACN 121974467 ACN121974467 ACN 121974467ACN-121974467-A

Abstract

The invention relates to the technical field of water treatment, in particular to a preparation method of a high-concentration fluorine-containing wastewater remover, which comprises the steps of crushing oyster shells which are determined to be qualified based on thermal decomposition temperature to obtain oyster shell powder, determining the mole ratio of strontium phosphate to strontium phosphate of strontium carbonate and disodium hydrogen phosphate based on the calcium dissolution rate of the oyster shell powder which is qualified in pretreatment to form a fluorine-fixing skeleton by mixing, determining the adding strategy of calcium hydroxide and aluminum trichloride based on the acid-base buffer index of the fluorine-fixing skeleton to obtain a mixed material, performing a simulated fluorine-fixing performance test on the mixed material, and determining whether the structure of the fluorine-fixing skeleton is complete based on the comparison result of the fluorine ion removal rate and the preset fluorine ion removal rate to obtain a qualified fluorine-containing wastewater remover finished product. The invention solves the technical problems of complex process and high cost in the prior art.

Inventors

CHAI LI
SU ZAICHUN
CUI WANZHE
DONG QINGHAI

Assignees

宁波希凯泰节能材料科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251211

Claims (10)

1. A preparation method of a high-concentration fluorine-containing wastewater remover is characterized by comprising the following steps of, Crushing oyster shells which are determined to be qualified in pretreatment based on the thermal decomposition temperature to obtain oyster shell powder; determining the strontium-phosphorus molar ratio of strontium carbonate and disodium hydrogen phosphate based on the calcium dissolution rate of pretreated qualified oyster shell powder to form a fluorine-fixing skeleton by mixing; Determining an adding strategy of calcium hydroxide and aluminum trichloride based on the acid-base buffer index of the fluorine-fixing framework so as to obtain a mixed material by adding and mixing; And (3) carrying out fluorine fixing performance test on the mixed material, and determining whether the fluorine fixing skeleton structure is complete based on the comparison result of the fluorine ion removal rate and the preset fluorine ion removal rate so as to obtain a qualified fluorine-containing wastewater remover finished product.
2. The method for preparing a high-concentration fluorine-containing wastewater remover according to claim 1, wherein the pretreatment process of oyster shell comprises, Washing oyster shells with deionized water to remove surface impurities and soluble salts; drying at 105 ℃ to constant weight, crushing and grinding to 150 mesh sieve to obtain raw material powder; Heating to a preset thermal decomposition temperature range at 10 ℃ per min.
3. The method for preparing a high-concentration fluorine-containing wastewater remover according to claim 2, wherein the step of pulverizing oyster shells, which are determined to be qualified for pretreatment based on a thermal decomposition temperature, to obtain oyster shell powder comprises, Comparing the thermal decomposition temperature with a preset thermal decomposition temperature interval; based on the thermal decomposition temperature, placing the oyster shell powder in a preset thermal decomposition temperature range, and determining that the pretreated oyster shell powder is qualified; obtaining the oyster shell powder.
4. The method for preparing a high-concentration fluorine-containing wastewater remover according to claim 1, wherein the determination of the mole ratio of strontium to phosphorus comprises, Determining a strontium phosphorus molar ratio in a first functional relationship based on the calcium dissolution rate being greater than or equal to a preset calcium dissolution rate; the first functional relation is obtained by subtracting a product of a first compensation coefficient and a difference between a calcium dissolution rate and a preset calcium dissolution rate from a reference strontium phosphorus molar ratio, and the result is taken as the strontium phosphorus molar ratio.
5. The method for preparing a high-concentration fluorine-containing wastewater remover according to claim 1, wherein the determination of the mole ratio of strontium to phosphorus further comprises, Determining a strontium phosphorus molar ratio in a second functional relationship based on the calcium dissolution rate being less than a preset calcium dissolution rate; wherein the second functional relation is the product of the reference strontium phosphorus molar ratio plus the second compensation coefficient and the difference between the preset calcium dissolution rate and the preset calcium dissolution rate, and the obtained result is taken as the strontium phosphorus molar ratio.
6. The method for preparing the high-concentration fluorine-containing wastewater remover according to claim 1, wherein the acid-base buffer index of the fluorine-fixing skeleton is larger than or equal to a preset acid-base buffer index, the adding amount of calcium hydroxide is determined to be 5% -15% of the finished product mass percent of the fluorine-containing wastewater remover, and the adding amount of aluminum trichloride is determined to be 15% -30% of the finished product mass percent of the fluorine-containing wastewater remover.
7. The method for preparing the high-concentration fluorine-containing wastewater remover according to claim 1, wherein the acid-base buffer index of the fluorine-fixing skeleton is smaller than a preset acid-base buffer index, and the adding amount of calcium hydroxide is determined to be 15% -20% of the finished product mass percent of the fluorine-containing wastewater remover, and the adding amount of aluminum trichloride is determined to be 5% -15% of the finished product mass percent of the fluorine-containing wastewater remover.
8. The method for preparing a high-concentration fluorine-containing wastewater remover according to claim 1, wherein the integrity of the fluorine-fixing skeleton structure is determined based on the fact that the fluorine ion removal rate is greater than or equal to a preset fluorine ion removal rate.
9. The method for preparing a high-concentration fluorine-containing wastewater remover according to claim 1, wherein the incomplete fluorine-fixing skeleton structure is determined based on that the fluorine ion removal rate is smaller than a preset fluorine ion removal rate.
10. The high-concentration fluorine-containing wastewater remover obtained by the preparation method according to any one of claims 1 to 9, which is characterized by comprising the following components in percentage by mass: 10-60% of oyster shell powder, 5-20% of calcium hydroxide, 0.5-2% of strontium carbonate, 0.5-3% of disodium hydrogen phosphate and 5-30% of aluminum trichloride.

Description

Preparation method of high-concentration fluorine-containing wastewater remover Technical Field The invention relates to the technical field of water treatment, in particular to a high-concentration fluorine-containing wastewater remover. Background The high-concentration fluorine-containing wastewater mainly originates from industries such as photovoltaic silicon wafer etching, semiconductor cleaning, fluorine chemical industry, aluminum smelting and the like, and because a large amount of raw materials such as hydrofluoric acid, ammonium fluoride and the like are used, the concentration of fluorine ions in the wastewater is extremely high (for example, the fluorine chemical wastewater reaches 1000-5000 mg/L), the wastewater has strong acidity, high salinity and biotoxicity, and often contains heavy metals and organic pollutants, the conventional technology is difficult to purify efficiently, and the fluorine pollution has bioaccumulation and long-distance migration, can enter an ecological system through water body and atmospheric sedimentation, is enriched in benthos and is amplified through a food chain. Long-term exposure to humans can lead to fluorosis, fluorosis dental and cardiovascular damage, as well as destroy aquatic organism diversity. The current treatment methods of the fluoride-containing wastewater commonly used in industry comprise a chemical precipitation method, a coagulating sedimentation method, an adsorption method and the like, wherein the chemical precipitation method is to add calcium salt (such as lime and calcium chloride) and fluoride ions to form calcium fluoride precipitates. The method can treat wastewater with high fluorine concentration, has the advantages of easily obtained raw materials and high cost benefit, but has the problems of large sludge yield, high water content of the sludge, poor sedimentation performance caused by too small particle size of calcium fluoride and the like, and can only reduce the fluorine ion concentration to about 15-20 mg/L, so that strict emission standard is difficult to reach, adopts coagulants such as aluminum salt, ferric salt and the like to remove the fluorine ions through flocculation, has simple process and easy operation, is suitable for large-scale treatment, also has large sludge yield and more factors influencing the fluorine ion removal efficiency, and adopts the adsorption method to remove the fluorine ions by utilizing the special affinity of the adsorption material, and has the advantages of simplicity, high efficiency, economy, small treatment water quantity, pretreatment requirement and limited adsorption capacity of the adsorbent. The Chinese patent publication No. CN119912012A discloses a fluorine removing agent for deep fluorine removal and a preparation method thereof, wherein the fluorine removing agent for deep fluorine removal comprises the following raw materials, by weight, 2-5 parts of chitosan, 65-90 parts of polyaluminium chloride, 5-15 parts of magnesium oxide, 1-5 parts of titanium dioxide, 1-5 parts of manganese oxide and 1-5 parts of lanthanum oxide. The fluorine removing agent has the beneficial effects that the fluorine removing agent is free from the constraint of the traditional calcium salt, key catalysts (such as titanium dioxide, manganese dioxide and other transition metal oxides) are introduced by selecting on the basis of controlling compatible components and the synthetic reaction process, the fluorine removing agent has a catalytic function on the complex reaction, the adsorption capacity of the fluorine removing agent can be improved, and the micro-flocculation nucleus is provided for generating the adsorption wrapping function in a long position. The fluorine ion content of the pretreated fluorine-containing wastewater (the fluorine ion content is below 20 mg/L) can be reduced to below 2mg/L, and the fluorine ion removal rate is above 90%. From this, the fluorine removal agent for deep fluorine removal and the preparation method thereof have the following problems: 1. the formula contains rare earth elements such as lanthanum oxide, and the raw materials are expensive and unstable in supply. 2. The method is only suitable for the advanced treatment stage of the low-concentration fluorine-containing wastewater, and lacks effective treatment capability for the original high-concentration fluorine-containing wastewater generated in the industries of photovoltaics, semiconductors and the like. Disclosure of Invention Therefore, the invention provides a preparation method of a high-concentration fluorine-containing wastewater remover, which is used for solving the problems of complex process and high cost in the prior art. In order to achieve the above object, the present invention provides a method for preparing a high-concentration fluorine-containing wastewater remover, comprising: crushing oyster shells which are determined to be qualified in pretreatment based on the thermal decomposition temper