CN113184855A - Resource comprehensive utilization method of phosphogypsum and potassium feldspar - Google Patents
Resource comprehensive utilization method of phosphogypsum and potassium feldspar Download PDFInfo
- Publication number
- CN113184855A CN113184855A CN202110431845.6A CN202110431845A CN113184855A CN 113184855 A CN113184855 A CN 113184855A CN 202110431845 A CN202110431845 A CN 202110431845A CN 113184855 A CN113184855 A CN 113184855A
- Authority
- CN
- China
- Prior art keywords
- phosphogypsum
- potassium
- filtrate
- potassium feldspar
- leaching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/08—Compounds containing halogen
- C01B33/10—Compounds containing silicon, fluorine, and other elements
- C01B33/103—Fluosilicic acid; Salts thereof
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
- C05G1/00—Mixtures of fertilisers belonging individually to different subclasses of C05
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Pest Control & Pesticides (AREA)
- Fertilizers (AREA)
Abstract
The invention discloses a resource comprehensive utilization method of phosphogypsum and potassium feldspar, which comprises the steps of mixing the phosphogypsum and the potassium feldspar in proportion, grinding the mixture to 200-400 meshes, and roasting and activating the mixture at the temperature of 300-1000 ℃ for 1-5 hours to obtain mixed ore; performing acid leaching reaction on the obtained mixed ore and hydrochloric acid at the temperature of 20-60 ℃, and performing solid-liquid separation after 0.5-3 hours to obtain leaching residue and leaching liquid; cooling and crystallizing the obtained leachate at-20-25 ℃ for 1-6 hours, and then carrying out solid-liquid separation to obtain filtrate and potassium fluosilicate; sequentially removing calcium from the obtained filtrate by using sulfuric acid, and neutralizing by using ammonia water step by step to remove aluminum, iron and magnesium impurities to obtain refined filtrate; and (4) supplementing phosphorus to the obtained refined filtrate, and then evaporating and concentrating to prepare the high-concentration NPK compound fertilizer. The method adopts roasting to activate the potassium feldspar, and simultaneously can also add calcium salt to reduce the roasting temperature; the soluble potassium can be obtained by leaching dilute acid at low temperature, and then the NPK compound fertilizer is prepared. Meanwhile, potassium fluosilicate products are obtained through low-temperature crystallization, so that the problem that subsequent crystallization is separated out to block the pipeline is solved.
Description
Technical Field
The invention belongs to the technical field of inorganic chemical industry, and particularly relates to a resource comprehensive utilization method of phosphogypsum and potassium feldspar.
Background
The phosphogypsum is solid waste discharged in the wet-process phosphoric acid production, and 4-5 t of phosphogypsum is generated every 1t of phosphoric acid production. The main component of the phosphogypsum is CaSO4·2H2And O, the pH value is 1.5-4.5, the phosphogypsum is acidic, and the phosphogypsum usually contains undecomposed phosphorite, phosphoric acid, calcium fluoride, iron-aluminum oxide, acid insoluble substances, organic substances and other impurities which are not washed clean and is slightly soluble in water. With the rapid development of the phosphate fertilizer industry in China, the discharge amount of the phosphogypsum is in a greatly increasing trend year by year. The discharge of the phosphogypsum not only pollutes the environment, but also occupies a large amount of land, enterprises also need to invest a large amount of slag yard construction capital and operation management cost, the comprehensive utilization of the phosphogypsum is listed as a resource key project by the nation, the comprehensive utilization and harmless treatment of the phosphogypsum are well done to become an important task of the phosphorus chemical industry, and the method has important significance for saving natural resources, protecting the ecological environment, building a conservation-oriented society, developing the recycling economy and realizing the sustainable development of the industry. Currently, phosphorus chemical industry enterprises in China face double pressure of resources and environment, and sustainable development is seriously challenged; the industrial chain is not perfect, the product structure is not rich, and the added value of the product is low. At present, an effective technology is lacked for high-value utilization of phosphogypsum, and reasonable connection of upstream and downstream industries is realized.
The potash feldspar is a typical non-water-soluble potassium-containing ore bed, is widely distributed in China and has large reserves. Potassium feldspar has a stable tetrahedral structure, and is difficult to decompose by common acid and alkali, so how to efficiently, environmentally and economically extract soluble potassium from potassium feldspar becomes the current researchAn important subject is to be solved. According to the report of the literature, a fluorine-containing substance can be additionally added to corrode potassium feldspar to extract soluble potassium, but fluorine has strong corrosivity and danger and brings great difficulty to experimental equipment and operation, and particularly, a part of fluorine enters a solution and brings great difficulty to subsequent fluorine removal and product quality. Furthermore, phosphogypsum contains a certain amount of fluorine due to potassium fluosilicate (K)2SiF6) The solubility is low, and K is very easy to be used for potassium and fluorine in the pickle liquor at room temperature2SiF6The form of (2) crystallizes out and blocks the pipeline. Can consider K2SiF6Crystallizing out first, and K2SiF6Is an important sylvite product and is widely used for wood corrosion prevention, ceramic manufacture, aluminum and magnesium smelting, optical glass manufacture, mica synthesis, porcelain glaze manufacture and the like. Furthermore, by K2SiF6Can also be used for preparing potassium sulfate, anhydrous hydrogen fluoride, potassium dihydrogen phosphate and other products with high added value.
The phosphate fertilizer and the potash fertilizer are used as nutrient element fertilizers of crops and play an extremely important role in the life metabolic process of the crops. However, in China, the yield and the dosage of phosphate fertilizers, potassium fertilizers and compound fertilizers thereof are insufficient, and the proportion of nitrogen, phosphorus and potassium applied to the fertilizers is seriously imbalanced, and the main reason is that the comprehensive utilization rate of phosphate rock and potassium ore resources in China is low, so that the proportion of phosphate fertilizers or compound fertilizers with high phosphorus and potassium in the production of the fertilizers in China is too low.
The extraction of potassium is mainly from soluble potassium salt deposit, but is seriously deficient in China. According to statistics, the storage capacity of the water-soluble potassium salt in the world of 2012 is converted into K2The O accounts for 95.52 hundred million tons, the Chinese accounts for 2.1 hundred million tons, accounts for about 2.2 percent of the total reserves in the world, is mainly distributed in the Qinghai Kerr salt lake and the Xinjiang Apocynum venetum salt lake, and is inconvenient to develop and utilize. The water-insoluble potassium-containing ore bed in China is rich in reserves of over 200 hundred million tons and is mostly distributed in middle and eastern agricultural developed areas.
Disclosure of Invention
The invention aims to provide a resource comprehensive utilization method of phosphogypsum and potassium feldspar and simultaneously obtain potassium fluosilicate and an NPK compound fertilizer.
In order to achieve the purpose, the technical scheme is as follows:
the resource comprehensive utilization method of the phosphogypsum and the potassium feldspar comprises the following steps of:
(1) roasting: mixing the phosphogypsum and the potassium feldspar in proportion, grinding to 200-400 meshes, and roasting and activating at the temperature of 300-1000 ℃ for 1-5 hours to obtain mixed ore;
(2) acid leaching: performing acid leaching reaction on the obtained mixed ore and hydrochloric acid at the temperature of 20-60 ℃, and performing solid-liquid separation after 0.5-3 hours to obtain leaching residue and leaching liquid;
(3) cooling and crystallizing: cooling and crystallizing the obtained leachate at-20-25 ℃ for 1-6 hours, and then carrying out solid-liquid separation to obtain filtrate and potassium fluosilicate;
(4) purifying the filtrate: sequentially removing calcium from the obtained filtrate by using sulfuric acid, and neutralizing by using ammonia water step by step to remove aluminum, iron and magnesium impurities to obtain refined filtrate;
(5) preparing an NPK compound fertilizer; and (4) supplementing phosphorus to the obtained refined filtrate, and then evaporating and concentrating to prepare the high-concentration NPK compound fertilizer.
According to the scheme, the step 2 also comprises the step of circulating acid leaching: and (3) supplementing acid to the obtained leaching solution, and then circularly treating the solid-liquid separation of the next batch of mixed ore for a plurality of times to obtain filter residue and P, K-enriched filtrate. The number of recycling times is 2-8, preferably 3-5.
According to the scheme, P in the phosphogypsum is P2O5Content of 2-15 wt%, K in potassium feldspar2The content of O is 7-15 wt%.
According to the scheme, in order to reduce the roasting temperature, calcium salt is also added in the step (1) as a cosolvent; the calcium salt is one or mixture of calcium chloride, calcium sulfate, calcium oxide and calcium carbonate, and the addition amount is 2-20 wt% of potassium feldspar.
According to the scheme, the concentration of the hydrochloric acid used in the step (2) is 5-20%, and the dosage is 1mL/g according to the liquid-solid ratio (2-6).
According to the scheme, the potassium fluosilicate is added in the step (3) as seed crystal, and the addition amount is 10-100 g/L.
Part of the obtained potassium fluosilicate can be used as crystal seeds, and part of the obtained potassium fluosilicate can be used as products for sale, or can be used for preparing products with high added values, such as potassium sulfate, anhydrous hydrogen fluoride, potassium dihydrogen phosphate and the like.
According to the scheme, calcium sulfate is removed in the step (4):
according to n (Ca)2+):n(SO4 2-) 1: (0.8-1.2) adding 50-98 wt% of sulfuric acid solution, wherein the reaction temperature is 30-90 ℃, the stirring speed is 400-1000 r/min, and the reaction time is 0.5-3 h.
According to the scheme, ammonia water in the step (4) is neutralized to remove aluminum, iron and magnesium impurities:
and adjusting the pH value of the solution by using an ammonia water solution to perform fractional precipitation and impurity removal, slowly adjusting the pH value to 3.5, precipitating and removing iron, precipitating and removing aluminum when the pH value is 6.5, and precipitating and removing magnesium when the pH value is 9.
According to the scheme, in the phosphorus supplementing process in the step (5), one or any mixture of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate and diammonium hydrogen phosphate is added. The addition amount of the N + P in the high-concentration NPK compound fertilizer2O5+K2The proportion of O is more than or equal to 40 percent (mass).
Since the potassium feldspar has a stable structure and does not react with other acids except hydrofluoric acid, hydrofluoric acid or fluoride salt (such as calcium fluoride) is generally added in the process of decomposing the potassium feldspar by the acid. However, fluorine has strong corrosivity and dangerousness, great difficulty is brought to experimental equipment and operation, and particularly, a part of fluorine enters a solution, great difficulty is brought to subsequent solution defluorination and product quality. The invention utilizes roasting method to activate potassium feldspar, then utilizes dilute acid to leach soluble potassium at low temperature, and can not bring difficulty to equipment and subsequent product quality, calcium salt can be added as an activating agent for reducing the activation temperature, while common calcium salts such as calcium chloride, calcium sulfate, calcium oxide and calcium carbonate are cheap and easy to obtain, and some solid wastes such as alkali residue in soda industry, phosphogypsum in wet process phosphoric acid industry and the like can be considered. The ion concentration of the leachate obtained after the phosphogypsum and the potassium feldspar are treated by hydrochloric acid is low, and enrichment is needed, and the ion concentration, particularly the concentration of P, K, is enriched by adopting a leachate circulating mineral leaching method. The number of cycles is critical, however, because the leachate is also enriched in calcium, magnesium, iron and aluminium, the concentration of which strongly influences the P, K concentration. Meanwhile, in the process of experimental solid-liquid separation, potassium fluosilicate is easy to crystallize and separate out, and pipelines are blocked certainly in engineering. Therefore, the invention utilizes the characteristic of low solubility of potassium fluosilicate to obtain potassium fluosilicate by low-temperature crystallization, avoids the problem of pipeline blockage, and part of the obtained potassium fluosilicate can be used as crystal seeds to return to the process, and part of the obtained potassium fluosilicate can be sold as products, or can be used for preparing products with high added value, such as potassium sulfate, anhydrous hydrogen fluoride, potassium dihydrogen phosphate and the like.
The invention innovatively provides a new process for preparing potassium fluosilicate and NPK compound fertilizer from phosphogypsum and potassium feldspar, fluoride is not added in the new process, potassium feldspar is activated by roasting, and calcium salt can be added to reduce the temperature of co-firing; the soluble potassium can be obtained by leaching dilute acid at low temperature, and further the NPK compound fertilizer urgently needed by the country is prepared. Meanwhile, by utilizing the characteristic of low solubility of potassium fluosilicate, potassium fluosilicate products are obtained by low-temperature crystallization, so that the problem that the pipeline is blocked due to the precipitation of potassium fluosilicate crystals in the subsequent solid-liquid separation is solved.
Compared with the prior art, the invention has the beneficial effects that:
(1) the method utilizes the roasting method to activate the potassium feldspar, does not add fluorine, does not cause the problems of equipment corrosion, safety, subsequent product quality and the like, and the used calcium salt activating agents are generally low in price and easy to obtain, and some solid wastes such as caustic sludge in the soda industry and phosphogypsum in the wet-process phosphoric acid industry can be considered.
(2) The invention utilizes the characteristic of low solubility of potassium fluosilicate to obtain potassium fluosilicate by low-temperature crystallization, avoids the problem of pipeline blockage and can obtain potassium fluosilicate products at the same time.
(3) The leaching agent dilute hydrochloric acid used by the invention has wide sources, is an industrial byproduct, and solves the problem of the outlet of the byproduct hydrochloric acid.
(4) Many production devices of the invention 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.
(5) 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: the invention discloses a process flow schematic diagram for recycling comprehensive utilization of phosphogypsum and potassium feldspar.
Detailed Description
The following examples further illustrate the technical solutions of the present invention, but should not be construed as limiting the scope of the present invention.
The process flow chart of the invention for preparing potassium fluosilicate and NPK compound fertilizer by using phosphogypsum and potassium feldspar is shown in figure 1, and comprises the following steps:
(1) roasting: mixing the phosphogypsum and the potassium feldspar in proportion, grinding to 200-400 meshes, and roasting and activating at the temperature of 300-1000 ℃ for 1-5 hours to obtain mixed ore; p in the phosphogypsum2O5Content of 2-15 wt%, K in potassium feldspar2The O content is 7-15 wt%; calcium salt can also be added as a cosolvent; the calcium salt is one or mixture of calcium chloride, calcium sulfate, calcium oxide and calcium carbonate, and the addition amount is 2-20 wt% of potassium feldspar.
(2) Acid leaching: performing acid leaching reaction on the obtained mixed ore and hydrochloric acid at the temperature of 20-60 ℃, and performing solid-liquid separation after 0.5-3 hours to obtain leaching residue and leaching liquid; the concentration of the hydrochloric acid is 5-20%, and the dosage is 1mL/g according to the liquid-solid ratio (2-6).
(3) And (3) circulating acid leaching: and (3) supplementing acid to the obtained leaching solution, and then circularly treating the solid-liquid separation of the next batch of mixed ore for a plurality of times to obtain filter residue and P, K-enriched filtrate. The number of recycling times is 2-8, preferably 3-5.
(4) Cooling and crystallizing: cooling and crystallizing the obtained leachate at-20-25 ℃ for 1-6 hours, and then carrying out solid-liquid separation to obtain filtrate and potassium fluosilicate; potassium fluosilicate can be added as seed crystal, and the addition amount of the potassium fluosilicate is 10-100 g/L. Part of the obtained potassium fluosilicate can be used as crystal seeds, and part of the obtained potassium fluosilicate can be used as products for sale, or can be used for preparing products with high added values, such as potassium sulfate, anhydrous hydrogen fluoride, potassium dihydrogen phosphate and the like.
(5) Purifying the filtrate: sequentially removing calcium from the obtained filtrate by using sulfuric acid, and neutralizing by using ammonia water step by step to remove aluminum, iron and magnesium impurities to obtain refined filtrate;
the method specifically comprises the following steps: according to n (Ca)2+):n(SO4 2-) 1: (0.8-1.2) adding 50-98 wt% of sulfurAcid solution, the reaction temperature is 30-90 ℃, the stirring speed is 400-1000 r/min, and the reaction time is 0.5-3 h; the obtained product calcium sulfate is used as the calcium salt raw material in the step (1). And adjusting the pH value of the solution by using an ammonia water solution to perform fractional precipitation and impurity removal, slowly adjusting the pH value to 3.5, precipitating and removing iron, precipitating and removing aluminum when the pH value is 6.5, and precipitating and removing magnesium when the pH value is 9.
(6) Preparing an NPK compound fertilizer; and (4) supplementing phosphorus to the obtained refined filtrate, and then evaporating and concentrating to prepare the high-concentration NPK compound fertilizer. The phosphorus supplementing process is to add one or any mixture of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate and diammonium hydrogen phosphate. The addition amount of the N + P in the high-concentration NPK compound fertilizer2O5+K2The proportion of O is more than or equal to 40 percent (mass).
The phosphogypsum used in the following examples is from a company in Hubei, and the main chemical composition of the phosphogypsum is shown in Table 1; the potassium feldspar used was from wavay (sunshine) mining ltd, cigarette end, and the chemical composition of the ore sample is shown in table 2.
Table 1 phosphogypsum main chemical composition wt.%
TABLE 2 Potassium feldspar content wt%
Example 1
(1) Roasting: 60g of phosphogypsum, 20g of potassium feldspar and 2g of calcium carbonate are mixed and ground to 200-400 meshes, and then the mixture is roasted at 600 ℃ for 3 hours for later use.
(2) Acid leaching: and (3) carrying out leaching reaction on the roasted and activated mixed ore and 320mL of hydrochloric acid solution (the mass concentration is 15%) at 50 ℃, and carrying out solid-liquid separation after 2 hours to obtain leaching slag and leaching liquid.
(3) And (3) circulating acid leaching: and (3) supplementing acid to the leachate obtained in the step (1) and then recycling the next batch of minerals according to the addition amount of hydrochloric acid and the liquid-solid ratio in the step (2), and repeating the step (2) for 3 times to perform solid-liquid separation to obtain filter residue and the filtrate enriched with P, K.
(4) Cooling and crystallizing: and (4) adding 60g/L of potassium fluosilicate into the filtrate obtained in the step (3) to be used as seed crystals, cooling and crystallizing at the temperature of 0 ℃ for 2 hours, and then carrying out solid-liquid separation to obtain the filtrate and potassium fluosilicate. The detection shows that the potassium fluosilicate product meets the national standard.
(5) Purifying the filtrate: the filtrate obtained in the step (4) is processed according to the formula of n (Ca)2+):n(SO4 2-) A 65% sulfuric acid solution was added at a ratio of 1:1.2, and calcium removal reaction was performed at 60 ℃ under stirring at 800 rpm for 2 hours, followed by solid-liquid separation. Adding ammonia water into the obtained filtrate to slowly adjust the pH value to 3.5 to generate white precipitate, continuously adding ammonia water into the filtrate after filtration and separation to adjust the pH value to 6.5 to generate white precipitate, adding ammonia water into the filtrate after filtration and separation again to adjust the pH value to 9 to generate white precipitate, and performing filtration and separation to obtain filter residue and purified filtrate.
(6) Preparing an NPK compound fertilizer: adding 5g of phosphoric acid serving as a phosphorus supplement agent into the purified filtrate obtained in the step (5), and then performing evaporation concentration at 110 ℃ until the solid content in the filtrate is more than 500g/L to prepare the NPK compound fertilizer, wherein detection shows that N, P in the compound fertilizer2O5、K2The contents of O and Cl are respectively 11.6%, 28.7%, 4.8% and 11.5%, which meet the national standard and belong to low-chlorine high-concentration NPK compound fertilizer.
Example 2
(1) Roasting: mixing 50g of phosphogypsum, 30g of potassium feldspar and 4g of calcium chloride, grinding to 200-mesh 400-mesh, and roasting at 400 ℃ for 2 hours for later use.
(2) Acid leaching: and (3) carrying out leaching reaction on the roasted and activated mixed ore and 160mL of hydrochloric acid solution (the mass concentration is 20%) at 50 ℃, and carrying out solid-liquid separation after 2 hours to obtain leaching slag and leaching liquid.
(3) And (3) circulating acid leaching: and (3) supplementing acid to the leachate obtained in the step (2) and then recycling the next batch of minerals according to the addition amount of hydrochloric acid and the liquid-solid ratio in the step (2), and carrying out solid-liquid separation after repeating the step (2) for 4 times to obtain filter residue and the filtrate enriched with P, K.
(4) Cooling and crystallizing: and (4) adding 60g/L of potassium fluosilicate into the filtrate obtained in the step (3) to be used as seed crystals, cooling and crystallizing at the temperature of 5 ℃ for 3 hours, and then carrying out solid-liquid separation to obtain the filtrate and potassium fluosilicate. The detection shows that the potassium fluosilicate product meets the national standard.
(5) Purifying the filtrate: the filtrate obtained in the step (4) is processed according to the formula of n (Ca)2+):n(SO4 2-) A 75% sulfuric acid solution was added at a ratio of 1:1, and calcium removal reaction was performed at 60 ℃ under 500 rpm stirring, and solid-liquid separation was performed after 0.5 h. Adding ammonia water into the obtained filtrate to slowly adjust the pH value to 3.5 to generate white precipitate, continuously adding ammonia water into the filtrate after filtration and separation to adjust the pH value to 6.5 to generate white precipitate, adding ammonia water into the filtrate after filtration and separation again to adjust the pH value to 9 to generate white precipitate, and performing filtration and separation to obtain filter residue and purified filtrate.
(6) Preparing an NPK compound fertilizer: adding 5g of ammonium phosphate as a phosphorus supplement agent into the purified filtrate obtained in the step (5), then carrying out evaporation concentration at 100 ℃ until the solid content in the filtrate is more than 500g/L, preparing NPK compound fertilizer, and detecting N, P in the compound fertilizer2O5、K2The contents of O and Cl are respectively 13.5%, 26.4%, 8.1% and 10.5%, which meet the national standard and belong to low-chlorine high-concentration NPK compound fertilizer.
Example 3
(1) Roasting: 40g of phosphogypsum and 40g of potassium feldspar are mixed and ground to 200-400 meshes, and then the mixture is roasted at 1000 ℃ for 5 hours for later use.
(2) Acid leaching: and (3) carrying out leaching reaction on the roasted and activated mixed ore and 160mL of hydrochloric acid solution (the mass concentration is 10%) at the temperature of 20 ℃, and carrying out solid-liquid separation after 0.5 hour to obtain leaching slag and leaching liquid.
(3) And (3) circulating acid leaching: and (3) supplementing acid to the leachate obtained in the step (2) and then recycling the next batch of minerals according to the addition amount of hydrochloric acid and the liquid-solid ratio in the step (2), and carrying out solid-liquid separation after repeating the step (2) for 2 times to obtain filter residue and the filtrate enriched with P, K.
(4) Cooling and crystallizing: and (4) adding 10g/L of potassium fluosilicate into the filtrate obtained in the step (3) to be used as seed crystals, cooling and crystallizing at the temperature of minus 20 ℃ for 1 hour, and then carrying out solid-liquid separation to obtain the filtrate and potassium fluosilicate. The detection shows that the potassium fluosilicate product meets the national standard.
(5) Purifying the filtrate: subjecting the product of step (2)Obtaining filtrate according to n (Ca)2+):n(SO4 2-) Adding 50% sulfuric acid solution at a ratio of 1:0.8, performing calcium removal reaction at 70 deg.C under stirring at 600 rpm, reacting for 3 hr, and performing solid-liquid separation. Adding ammonia water into the obtained filtrate to slowly adjust the pH value to 3.5 to generate white precipitate, continuously adding ammonia water into the filtrate after filtration and separation to adjust the pH value to 6.5 to generate white precipitate, adding ammonia water into the filtrate after filtration and separation again to adjust the pH value to 9 to generate white precipitate, and performing filtration and separation to obtain filter residue and purified filtrate.
(6) Preparing an NPK compound fertilizer: adding 6g of diammonium hydrogen phosphate serving as a phosphorus supplement agent into the purified filtrate obtained in the step (5), then performing evaporation concentration at 100 ℃ until the solid content in the filtrate is more than 500g/L, preparing the NPK compound fertilizer, and detecting N, P in the compound fertilizer2O5、K2The contents of O and Cl are respectively 20.8%, 25.6%, 4.7% and 12.6%, which meet the national standard and belong to low-chlorine high-concentration NPK compound fertilizer.
Example 4
(1) Roasting: 30g of phosphogypsum, 50g of potassium feldspar and 10g of calcium sulfate are mixed and ground to 200-400 meshes, and then the mixture is roasted at 300 ℃ for 0.5 hour for later use.
(2) Acid leaching: and (3) carrying out leaching reaction on the roasted and activated mixed ore and 480mL of hydrochloric acid solution (the mass concentration is 20%) at 60 ℃, and carrying out solid-liquid separation after 3 hours to obtain leaching slag and leaching liquid.
(3) And (3) circulating acid leaching: and (3) supplementing acid to the leachate obtained in the step (2) and then recycling the next batch of minerals according to the addition amount of hydrochloric acid and the liquid-solid ratio in the step (2), and carrying out solid-liquid separation after repeating the step (2) for 8 times to obtain filter residue and the filtrate enriched with P, K.
(4) Cooling and crystallizing: and (4) adding 100g/L of potassium fluosilicate into the filtrate obtained in the step (3) to be used as seed crystals, cooling and crystallizing at the temperature of 20 ℃ for 6 hours, and then carrying out solid-liquid separation to obtain the filtrate and potassium fluosilicate. The detection shows that the potassium fluosilicate product meets the national standard.
(5) Purifying the filtrate: the filtrate obtained in the step (4) is processed according to the formula of n (Ca)2+):n(SO4 2-) Adding 98% sulfuric acid solution at a ratio of 1:1.2, stirring at 90 deg.C and 1000 rpmCalcium removal reaction is carried out under the condition, and solid-liquid separation is carried out after 2 hours of reaction. Adding ammonia water into the obtained filtrate to slowly adjust the pH value to 3.5 to generate white precipitate, continuously adding ammonia water into the filtrate after filtration and separation to adjust the pH value to 6.5 to generate white precipitate, adding ammonia water into the filtrate after filtration and separation again to adjust the pH value to 9 to generate white precipitate, and performing filtration and separation to obtain filter residue and purified filtrate.
(6) Preparing an NPK compound fertilizer: adding 10g of ammonium dihydrogen phosphate serving as a phosphorus supplement agent into the purified filtrate obtained in the step (5), then performing evaporation concentration at 100 ℃ until the solid content in the filtrate is more than 500g/L, preparing the NPK compound fertilizer, and detecting N, P in the compound fertilizer2O5、K2The contents of O and Cl are respectively 16.2%, 20.8%, 6.7% and 10.5%, which meet the national standard and belong to low-chlorine high-concentration NPK compound fertilizer.
Claims (9)
1. The resource comprehensive utilization method of the phosphogypsum and the potassium feldspar is characterized by comprising the following steps of:
(1) roasting: mixing the phosphogypsum and the potassium feldspar in proportion, grinding to 200-400 meshes, and roasting and activating at the temperature of 300-1000 ℃ for 1-5 hours to obtain mixed ore;
(2) acid leaching: performing acid leaching reaction on the obtained mixed ore and hydrochloric acid at the temperature of 20-60 ℃, and performing solid-liquid separation after 0.5-3 hours to obtain leaching residue and leaching liquid;
(3) cooling and crystallizing: cooling and crystallizing the obtained leachate at-20-25 ℃ for 1-6 hours, and then carrying out solid-liquid separation to obtain filtrate and potassium fluosilicate;
(4) purifying the filtrate: sequentially removing calcium from the obtained filtrate by using sulfuric acid, and neutralizing by using ammonia water step by step to remove aluminum, iron and magnesium impurities to obtain refined filtrate;
(5) preparing an NPK compound fertilizer; and (4) supplementing phosphorus to the obtained refined filtrate, and then evaporating and concentrating to prepare the high-concentration NPK compound fertilizer.
2. A resource comprehensive utilization method of phosphogypsum and potassium feldspar according to claim 1, characterized in that the step 2 further comprises the step of circulating acid leaching: and (3) supplementing acid to the obtained leaching solution, and then circularly treating the solid-liquid separation of the next batch of mixed ore for a plurality of times to obtain filter residue and P, K-enriched filtrate.
3. A resource comprehensive utilization method of phosphogypsum and potassium feldspar according to claim 1, characterized in that P in phosphogypsum is P2O5Content of 2-15 wt%, K in potassium feldspar2The content of O is 7-15 wt%.
4. A resource comprehensive utilization method of phosphogypsum and potassium feldspar according to claim 1, which is characterized in that calcium salt is added as a cosolvent in the step (1); the calcium salt is one or mixture of calcium chloride, calcium sulfate, calcium oxide and calcium carbonate, and the addition amount is 2-20 wt% of potassium feldspar.
5. A resource comprehensive utilization method of phosphogypsum and potassium feldspar according to claim 1, characterized in that the concentration of the hydrochloric acid used in the step (2) is 5-20%, and the dosage is (2-6):1mL/g according to the liquid-solid ratio.
6. A resource comprehensive utilization method of phosphogypsum and potassium feldspar according to claim 1, characterized in that potassium fluosilicate is added in the step (3) as a seed crystal, and the addition amount is 10-100 g/L.
7. A resource comprehensive utilization method of phosphogypsum and potassium feldspar according to claim 1, characterized in that the calcium is removed by sulfuric acid in the step (4):
according to n (Ca)2+):n(SO4 2-) 1: (0.8-1.2) adding 50-98 wt% of sulfuric acid solution, wherein the reaction temperature is 30-90 ℃, the stirring speed is 400-1000 r/min, and the reaction time is 0.5-3 h.
8. A resource comprehensive utilization method of phosphogypsum and potassium feldspar according to claim 1, characterized in that ammonia water in the step (4) is neutralized to remove aluminum, iron and magnesium impurities:
and adjusting the pH value of the solution by using an ammonia water solution to perform fractional precipitation and impurity removal, slowly adjusting the pH value to 3.5, precipitating and removing iron, precipitating and removing aluminum when the pH value is 6.5, and precipitating and removing magnesium when the pH value is 9.
9. A resource comprehensive utilization method of phosphogypsum and potassium feldspar according to claim 1, characterized in that in the step (5), one or any mixture of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate and diammonium hydrogen phosphate is added in the process of supplementing phosphorus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110431845.6A CN113184855A (en) | 2021-04-21 | 2021-04-21 | Resource comprehensive utilization method of phosphogypsum and potassium feldspar |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110431845.6A CN113184855A (en) | 2021-04-21 | 2021-04-21 | Resource comprehensive utilization method of phosphogypsum and potassium feldspar |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113184855A true CN113184855A (en) | 2021-07-30 |
Family
ID=76977947
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110431845.6A Pending CN113184855A (en) | 2021-04-21 | 2021-04-21 | Resource comprehensive utilization method of phosphogypsum and potassium feldspar |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113184855A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112898073A (en) * | 2021-01-14 | 2021-06-04 | 襄阳泽东化工集团有限公司 | Method for preparing NPK compound fertilizer by using phosphate tailings and potassium feldspar |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4486217A (en) * | 1981-05-22 | 1984-12-04 | Denryoku-Chuo-Kenkyusho | Compound solid fertilizer and manufacturing method thereof |
| CN100999423A (en) * | 2006-12-31 | 2007-07-18 | 合肥工业大学 | Method of preparing nitrogen phosphorus potassium complex fertilizer using potash feldspar |
| CN103073344A (en) * | 2013-01-23 | 2013-05-01 | 天脊煤化工集团股份有限公司 | Production method for high-concentration defluorinate nitronitrogen phosphorus and potassium compound fertilizer |
| CN104496726A (en) * | 2014-12-24 | 2015-04-08 | 金正大诺泰尔化学有限公司 | Method for calcining soil conditioner from phosphoric ore tailing, phosphogypsum and potassium feldspar |
| CN105367176A (en) * | 2015-12-02 | 2016-03-02 | 武汉工程大学 | Multi-element comprehensive utilization process for phosphorus-potassium associated ore |
| CN111732209A (en) * | 2020-07-23 | 2020-10-02 | 湖北祥云(集团)化工股份有限公司 | Method and device capable of effectively reducing scale of phosphogypsum backwater conveying pipeline |
-
2021
- 2021-04-21 CN CN202110431845.6A patent/CN113184855A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4486217A (en) * | 1981-05-22 | 1984-12-04 | Denryoku-Chuo-Kenkyusho | Compound solid fertilizer and manufacturing method thereof |
| CN100999423A (en) * | 2006-12-31 | 2007-07-18 | 合肥工业大学 | Method of preparing nitrogen phosphorus potassium complex fertilizer using potash feldspar |
| CN103073344A (en) * | 2013-01-23 | 2013-05-01 | 天脊煤化工集团股份有限公司 | Production method for high-concentration defluorinate nitronitrogen phosphorus and potassium compound fertilizer |
| CN104496726A (en) * | 2014-12-24 | 2015-04-08 | 金正大诺泰尔化学有限公司 | Method for calcining soil conditioner from phosphoric ore tailing, phosphogypsum and potassium feldspar |
| CN105367176A (en) * | 2015-12-02 | 2016-03-02 | 武汉工程大学 | Multi-element comprehensive utilization process for phosphorus-potassium associated ore |
| CN111732209A (en) * | 2020-07-23 | 2020-10-02 | 湖北祥云(集团)化工股份有限公司 | Method and device capable of effectively reducing scale of phosphogypsum backwater conveying pipeline |
Non-Patent Citations (1)
| Title |
|---|
| 毛小云: "废弃物农用功能化理论与技术", 华南理工大学出版社, pages: 160 - 370 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112898073A (en) * | 2021-01-14 | 2021-06-04 | 襄阳泽东化工集团有限公司 | Method for preparing NPK compound fertilizer by using phosphate tailings and potassium feldspar |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102351591B (en) | Method for highly water-soluble nitrophosphate fertilizer production through decomposition of rare earth-containing phosphate rock by nitric acid and for rare earth recovery | |
| CN102718200B (en) | Method for preparing industrial-grade phosphoric acid by decomposing mid-low-grade phosphorite with nitric acid | |
| CN100999423A (en) | Method of preparing nitrogen phosphorus potassium complex fertilizer using potash feldspar | |
| CN101348244B (en) | Preparation of ammonium potassium dihydrogen phosphate | |
| CN106185855B (en) | A kind of feed grade phosphoric acid by wet process deep-purifying method | |
| CN102126742B (en) | Method for producing chloride-based compound fertilizer and co-producing gypsum through decomposing phosphorite with hydrochloric acid | |
| CN101337657A (en) | Process for disassembling phosphate ore by mixed acid and coproducing potassium dihydrogen phosphate, hydrogen phosphate and combined fertilizer | |
| CN108396158A (en) | A kind of processing method of the complex salt crystal object of electrolytic manganese process | |
| CN104774125B (en) | A kind of method of the rich nitrogen sulfate fertilizer of utilization ardealite production and recovering rare earth | |
| CN105600763A (en) | Method for producing industrial monoammonium phosphate through fluoride salt purification method | |
| CN112898073B (en) | Method for preparing NPK compound fertilizer by using phosphate tailings and potassium feldspar | |
| CN101434386A (en) | Method for producing fine phosphate by using dilute acid to decompose middle and low grade phosphate ore using | |
| CN105272441A (en) | Process for production of liquid compound fertilizer by combination of decomposition of phosphate ore by use of nitric acid and removal of calcium by use of potassium salt | |
| CN113184855A (en) | Resource comprehensive utilization method of phosphogypsum and potassium feldspar | |
| CN102107888B (en) | Method for preparing potassium sulphate | |
| CN105000539A (en) | Method for producing potassium dihydrogen phosphate and potassium-ammonium dihydrogen phosphate through wet process phosphoric acid | |
| CN110217769B (en) | Method for producing calcium ammonium nitrate byproduct feed-grade DCP | |
| CN112758937B (en) | Method for preparing potassium fluosilicate and NPK compound fertilizer from associated phosphate-potassium ore | |
| CN106564926B (en) | A kind of method that hydrochloric acid decomposition phosphorus tailing prepares calcium sulfate and high magnesium compound fertilizer | |
| CN105480959A (en) | Method for producing monopotassium phosphate by fluoride salt purification process | |
| CN112725638A (en) | Method for strengthening leaching of potassium in potassium feldspar by using surfactant | |
| CN115092901B (en) | Method for preparing battery-grade ferric phosphate by decomposing phosphorite with nitric acid | |
| CN115215309A (en) | Method for producing industrial-grade phosphoric acid and recycling industrial-grade phosphoric acid by phosphorite-nitric acid method | |
| CN111517832B (en) | Separation method of P, Ca in medium-low grade phosphate ore and method for producing fertilizer | |
| US3840640A (en) | Production of fluoride-free nitrates |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |