Composite basic manganese chloride as well as preparation method and application thereof

Abstract

The invention discloses composite basic manganese chloride as well as a preparation method and application thereof, and belongs to the technical field of preparation of inorganic chemical products. The raw materials used in the preparation method are wide in source and lower in price, and the production process is simple in step and high in yield, so that the production cost is low; in addition, the preparation method provided by the invention comprises an impurity removal step, the content of harmful ions in the finally obtained basic manganese chloride product is extremely low, and adverse effects on animals and plants are not generated after the basic manganese chloride product is used; a nucleating agent and a surfactant are introduced in the preparation process, so that the product with a narrow and uniform particle size distribution range can be obtained, specific nutritional ingredients can be introduced into the product, and meanwhile, high-valence manganese ingredients can be prevented from being generated in the drying process, so that the obtained product is more easily absorbed and utilized by animals and plants; therefore, the obtained product can be better used as feed or plant fertilizer.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of inorganic chemical products, and specifically relates to a composite basic manganese chloride and a preparation method and application thereof. Background Art

[0002] Although the content of manganese in animals is very small, only 2~3mg / kg, it is an important element of life and plays a very important physiological function. Manganese is usually one of the elements necessary for animal bone development, brain function and reproductive function. In the body, manganese participates in the metabolism of carbohydrates, fats and proteins. When poultry lacks manganese, it will lead to abnormal bone development, short and thick leg bones, and lameness of sick birds; it will also lead to malformation of poultry embryos, short and thick legs, short wings, head deformities, and poor embryo development, thus reducing the hatching rate. When pigs, cattle and other livestock mammals lack manganese, growth and development will be stunted, and emaciation will occur; reproductive dysfunction, female animals have poor mammary development, prolonged estrus, difficulty in conception, miscarriage, stillbirth, and weak fetus; newborn animals have movement disorders, weak and sickly bodies, tremors, ataxia, and slow growth; bone deformities, shortened tubular bones, and gait stiffness or lameness. Manganese-deficient male animals have testicular degeneration and lose reproductive function.

[0003] In the prior art, the problem of manganese deficiency in livestock is generally improved by adding manganese-containing feed additives to feed, but the absorption rate of manganese in feed by livestock is low, only 3% to 4%, and most of the manganese ingested is excreted from the body through feces. In addition, when livestock eat high-calcium and high-phosphorus feed, the absorption of manganese is significantly reduced. The main sources of manganese in additives for animal feed and plant manganese fertilizers on the market can be divided into inorganic manganese and organic manganese. Among them, the inorganic manganese in feed additives or plant manganese fertilizers can be selected from one or more of MnO, MnSO4, MnCl2, MnCO3, etc., but there are large differences in the absorption and utilization of these manganese in animals or plants. The bioavailability of Mn in MnSO4 is better than that of MnO and MnCO3, and is close to that of MnCl2. Among them, the utilization rate of Mn in MnO is only about two-thirds of that of MnSO4, and MnCO3 is only about three-fifths of that of MnSO4. In fact, most of the single manganese element will be synthesized into manganese phytate in the animal stomach, forming insoluble compounds that are difficult to digest and utilize. However, after Mn is combined with organic matter such as methionine, citric acid and other complexing agents, the utilization and absorption rate of manganese elements will be improved. For example, manganese methionine can directly enter the intestines of livestock and poultry to be absorbed and participate in metabolism. Therefore, when choosing a suitable manganese additive, on the one hand, its addition cost should be considered, and on the other hand, its bioavailability should also be considered.

[0004] Although organic manganese sources have higher bioavailability than inorganic manganese sources, they are usually expensive and have low cost-effectiveness in the field of feed and plant micro-fertilizers. Currently, the organic manganese sources that are easily available on the market include glycine manganese, methionine manganese, hydroxymethionine manganese, etc. This type of amino acid manganese has a good effect, is easily absorbed by animal and plant matrices, and is not easy to interact with other components such as protein, starch, and sugar in feed. In addition, the excrement of animals after eating has little impact on the environment. However, the ligand of amino acid manganese is amino acid, which is expensive and has low cost advantage. In addition, the manganese content is low, and the amount of addition needs to be increased. The use of such products faces cost pressure in the feed production process.

[0005] The bioavailability of trace elements is closely related to the compound state of the elements. Inorganic trace elements can be dissolved in water or oxidized by air in the natural environment, and react chemically with other components in the air. Inorganic trace ions are prone to chemical reactions with other components in feed, generating relatively stable compounds that are not easily absorbed by animals and plants. Therefore, the total bioavailability of trace elements in inorganic salts is generally less than 20%. In addition, due to the high toxicity of inorganic trace heavy metal elements, the amount added to feed must be strictly controlled within the range permitted by the state.

[0006] At present, from the perspective of comprehensive cost-effectiveness, manganese used in feed additives and plant fertilizers is mainly manganese sulfate or manganese chloride. However, manganese sulfate is used as the feed additive because it is easy to deliquesce and will cause feed caking. In addition, potassium permanganate or hydrogen peroxide is often used to oxidize and remove impurities during the production process of manganese sulfate. The synthesized manganese sulfate product will have a small amount of manganese dioxide, potassium permanganate and other oxides. These oxides have high oxidation and catalytic properties and are easy to react with other nutrients in feed or plant fertilizers, such as protein, vitamins, divalent iron, fatty acids and other components to undergo redox reactions, affecting the quality and shelf life of feed or fertilizer. In addition, the sulfate content is high, and animals will discharge feces containing a large amount of sulfate after absorption and utilization. These sulfates will cause soil compaction and accelerate soil salinization. As a new type of feed additive, trace element basic salts have attracted much attention for their good palatability, good stability, effective inhibition of bacterial growth, low environmental pollution, and higher bioavailability than inorganic trace elements. However, the basic manganese chloride currently produced industrially still has problems such as low absorption efficiency and residual high-valent manganese ions. Summary of the invention

[0007] In view of the above-mentioned prior art, the present invention provides a composite basic manganese chloride and a preparation method and application thereof, so as to solve the technical problems of low absorption efficiency and residual high-valent manganese ions in the existing basic manganese chloride.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is to provide a method for preparing composite basic manganese chloride, comprising the following steps: S1: dissolving the manganese-containing material in water or acid solution to prepare a solution with a manganese ion concentration of 75-130 g / L; S2: Adjust the solution to weak acidity, then add metallic manganese to the solution, stir, filter, and repeat the above steps several times until Fe 3+ 、Al 3+ , Cu 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+ , Hg 2+ All less than 0.002g / L; S3: adding an impurity remover to the filtrate obtained in S2, stirring and filtering, then adding ammonium sulfide to the filtrate, continuing to stir and filter, to obtain a pure manganese solution; S4: Add a crystal nucleation agent to the pure manganese solution, adjust the pH of the pure manganese solution to 6-7, and then introduce a precipitant into the pure manganese solution for precipitation reaction until the D of the precipitated particles reaches 50 When the particle size reaches 6-8 μm, stop the precipitation reaction and stir at 20-55 °C for 10-24 h; S5: Add the surface modifier to the system obtained in S4, mix well and then flash dry at 250°C to obtain.

[0009] Based on the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, the manganese-containing material is industrial manganese chloride, industrial manganese carbonate or industrial manganese oxide; and the acid solution is hydrochloric acid solution.

[0011] Furthermore, the solution in S2 is adjusted to a weakly acidic pH of 6-6.5; the metallic manganese is ultrafine manganese powder, manganese granules, manganese blocks or manganese ingots; and the amount of metallic manganese added is 1.5 times the total amount of iron, aluminum, copper, antimony, chromium, arsenic, lead, cadmium and mercury detected in the solution.

[0012] Further, the impurity remover is at least one of manganese sulfide, manganese oxalate, manganese carbonate, manganese selenide, ammonium bicarbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium oxalate, potassium oxalate, sodium silicate, potassium silicate, sodium selenate, potassium selenate, sodium phosphate, potassium phosphate and lithium phosphate; the material-liquid ratio of the added impurity remover to the filtrate is 5kg:1m 3 The stirring time after adding the impurity remover is 1h; the amount of ammonium sulfide added is 1.5 times the zinc detected in the solution, and the stirring time after adding ammonium sulfide is 1~2h.

[0013] Furthermore, the crystal nucleus agent is at least one of selenoamino acid manganese, methionine manganese, manganese oxalate, manganese citrate, manganese gluconate, methionine manganese and manganese proteinate.

[0014] Furthermore, the mass ratio of the added nucleating agent to the manganese-containing material is 0.5~1:500.

[0015] Furthermore, the precipitant is at least one of ammonia gas, liquid ammonia, ammonia water, sodium hydroxide, potassium hydroxide and lithium hydroxide.

[0016] Furthermore, the surface modifier is at least one of glucose, sucrose, citric acid, ascorbic acid, amino acids, unsaturated fatty acids, salicylic acid, ethylene glycol, glycerol, ethyl acetate and butanone; and the mass ratio of the added surface modifier to the crystal nucleating agent is 3-3.1:1.

[0017] The beneficial effect of the above technical solution of the present invention is that in the impurity removal step, Fe 3+ and Al 3+ The method is based on the low solubility product of Fe(OH)3 and Al(OH)3 ions, which can be separated by adjusting the pH value to form a precipitate. 2+ and Fe 3+ Components can be oxidized by oxygen in the air to make Fe 2+ ions are converted to Fe 3+ The ions are then separated by obtaining a precipitate in their precipitation pH range.

[0018] In the impurity removal step, the present invention removes or reduces the Cu in the system by adding manganese powder, manganese block, manganese ingot, manganese granule and other metal manganese materials. 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+ , Hg 2+ The main principle of plasma content is Mn 2+ The electrode potential of Mn is different from that of the above ions. 0 / Mn 2+ The charge transfer between them is carried out by redox reaction, and the metal Mn is used to reduce the Cu in the replacement solution. 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+ , Hg 2+ Plasma.

[0019] In the process of impurity removal, the present invention also adds an impurity remover (at least one of manganese sulfide, manganese oxalate, manganese carbonate, manganese selenide, ammonium bicarbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium oxalate, potassium oxalate, sodium silicate, potassium silicate, sodium selenate, potassium selenate, sodium phosphate, potassium phosphate, and lithium phosphate) to the system. The basic principle is to use the characteristics of low solubility product constant and small solubility of carbonates, oxalates, silicates, hydroxides, etc. of specific metal ions to carry out chemical precipitation reaction, so that the metal ions to be separated are precipitated to achieve the purpose of purification. The amount of the impurity remover is determined based on the ion content in the raw material solution. In the process of impurity removal, in order to ensure the removal effect of impurity ions, the amount of the impurity remover is usually increased by 1% to 20% on the basis of theoretical calculation.

[0020] The present invention uses a crystal nucleating agent in the process of preparing basic manganese chloride. The purpose of using the crystal nucleating agent is to make the basic manganese chloride obtained by the reaction grow on the crystal nucleus, on the one hand, reduce the nucleation barrier of the basic manganese chloride, on the other hand, the agglomeration phenomenon in the reaction system can be well controlled, and the reaction can be promoted to proceed in the forward direction, so that the yield of the target product is higher, and the particles of the target product are more uniform, thereby obtaining a basic manganese chloride product with a narrow and uniform particle size distribution range. In addition, the addition of the crystal nucleating agent can also introduce specific nutrients into the basic manganese chloride product, making it easier for animals and plants to absorb and utilize, so that the obtained product can be better used as feed or plant fertilizer.

[0021] In the process of preparing basic manganese chloride, the present invention also uses a precipitant, and the precipitant can be selected from one or more of liquid ammonia, ammonia water, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc., and the amount thereof is calculated according to the stoichiometric ratio, and the actual amount added is usually reduced by 1% to 10% on the basis of the theoretical calculation. The present invention obtains Mn2(OH)3Cl by controlling the pH value, stirring speed, reaction temperature and other condition parameters, and the chemical reaction equation is: 2MnCl2+3NH3·H2O=Mn2(OH)3Cl↓+3NH4Cl In order to prevent MnCl2 from directly generating Mn(OH)2 in a large amount of strong alkaline environment, manganese chloride is usually kept in a slight excess to reduce the formation of by-product Mn(OH)2, so as to make the purity and yield of the target product basic manganese chloride higher.

[0022] In the process of preparing basic manganese chloride, a surfactant is added to the system. The purpose of adding the surfactant is to prevent uncontrollable agglomeration between the Mn2(OH)3Cl crystals obtained by the reaction, and to prevent Mn2(OH)3Cl from being oxidized by oxygen in the air during the drying process, thereby generating Mn 3+ , Mn 4+At the same time, after drying, the surfactant will adhere to the surface of the product, which is more conducive to the absorption of animals or plants.

[0023] The present invention also discloses a composite basic manganese chloride, which is prepared by the above-mentioned preparation method; the prepared composite basic manganese chloride has a D 50 Particle size is 5~10μm, D 90 The particle size is less than 15μm, the Mn element content is 53.0wt%~56.8wt%, the Cl element content is 16.5wt%~19.5wt%, the H2O content is 1wt~5wt%, the Ca element content is 0.01wt%~0.05wt%, the Se element content is 0.0001wt%~0.0005wt%, the P element content is 0.0001wt%~0.0003wt%, the Zn element content is 0.0015wt%~0.002wt%, and the Cr, Pb, Cd, As and Hg element contents are all less than 0.00003wt%.

[0024] The invention also discloses an application of the composite basic manganese chloride, specifically using the composite basic manganese chloride as an animal feed additive or a plant fertilizer additive.

[0025] The beneficial effects of the present invention are: 1. The preparation method of the present invention can use industrial-grade manganese chloride, a manganese chloride solution prepared by leaching rhodochrosite or manganese carbonate ore with hydrochloric acid, a reaction product of crude manganese carbonate and hydrochloric acid, a reaction product of crude manganese oxide and hydrochloric acid, or a mixed solution thereof as raw materials for production, which has a wider source of raw materials, a lower price, and a lower production cost.

[0026] 2. The method of the present invention has simple production process steps, low cost and high yield, and the method of the present invention contains an impurity removal step, and the basic manganese chloride product finally obtained has extremely low harmful ion content.

[0027] 3. The basic manganese chloride prepared by the method of the present invention has nanometer-scale primary crystals and micrometer-scale secondary particles, and the secondary particles have uniform particle size, narrow particle size distribution, good dispersion fluidity, are easy to dry, do not contain crystal water, are not easy to harden during long-term heavy pressure storage, and are conducive to storage and transportation.

[0028] 4. Basic manganese chloride Mn obtained by the present invention 2+The content is high, the impurity ion content is low, and it is rich in other life elements. It is not only green and environmentally friendly, but also rich in nutritional components and can be used as animal feed or plant fertilizer. In addition, the present invention adds a surface modifier during the preparation of basic manganese chloride, and the final product can remain stable at a high temperature of 280°C, is not easily oxidized, can withstand the temperature during the processing and granulation of feed or plant fertilizer, and will not be denatured during granulation; and the addition of the surface modifier can introduce glucose, sucrose, citric acid, ascorbic acid, amino acids, unsaturated fatty acids, salicylic acid, ethylene glycol, glycerol, ethyl acetate and other nutrients into the obtained basic manganese chloride product, which is more conducive to animal and plant absorption.

[0029] 5. The manganese concentration in the basic manganese chloride prepared by the method of the present invention is relatively higher (theoretical value can reach 55.97wt%), which is higher than 32.5wt% of manganese chloride monohydrate, and the addition amount in feed or plant fertilizer (the same addition amount calculated as manganese element) can be reduced, leaving more room for addition in the formula design of feed or plant fertilizer (the same addition level of manganese content can add more other functional auxiliary products).

[0030] 6. The basic manganese chloride prepared by the method of the present invention contains Cu 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+ , Hg 2+ The impurity ions are very low and it does not contain high-valent manganese phases such as KMnO4, MnO2, and Mn3O4, which can effectively prevent other nutrients in animal feed or plant fertilizer from being oxidized and destroyed.

[0031] 7. The basic manganese chloride prepared by the present invention is environmentally friendly and is a new feed additive that is safe, efficient, environmentally friendly, rich in nutrients and easy to store. DETAILED DESCRIPTION

[0032] The specific implementation modes of the present invention are described in detail below with reference to the embodiments.

[0033] Example 1 A composite basic manganese chloride is prepared by the following steps: (1) Add 500 kg of industrial grade crude manganese chloride (MnCl2·4H2O) (purity 95%) into a glass fiber reinforced plastic storage tank (volume 3m 3 ), stirred to completely dissolve, and the impurity ion content in the obtained solution was analyzed and tested, as follows: Ca 2+ :0.6g / L; Zn 2+ :0.2g / L;Cu2+ :0.03g / L;Fe 3+ :0.02g / L;Al 3+ :0.06g / L; Sb 3+ :0.005g / L; Cr 3+ :0.005g / L; As 3+ :0.005g / L; Pb 2+ :0.005g / L; Cd 2+ :0.015g / L; Hg 2+ <0.001g / L;pH 4.0~4.5; S2: Adjust the pH value of the solution to 6.3, then add ultrafine manganese powder 1.5 times the total amount of iron, aluminum, copper, antimony, chromium, arsenic, lead, cadmium and mercury detected in the solution under stirring, stir for 1 hour and filter; repeat the above operation several times until Fe in the solution is reduced to 0. 3+ 、Al 3+ , Cu 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+ , Hg 2+ All less than 0.002g / L; S3: Add manganese carbonate to the filtrate after filtration in S2, and the material-liquid ratio of the added manganese carbonate to the filtrate is 5kg:1m 3 , stirred for 1 hour and filtered; S4: Add the Zn detected in the solution to the filtrate obtained in S3 2+ Add 1.5 times the amount of ammonium sulfide as the total amount of heavy metal ions, continue stirring for 1 hour, then filter and set aside; S5: Add 1 kg of selenoamino acid manganese microcrystals as crystal nuclei to the filtrate obtained in S4, wherein the selenoamino acid manganese microcrystals are prepared by gradient multiple chelation (complexation) reaction between commercially available selenoamino acids and manganese ions [1]; adjust the pH value of the system to 6.5, then introduce ammonia gas under stirring, monitor the growth process of the precipitated particles in the system, and when the precipitated particles D 50 When the particle size reached 6 μm, stop passing ammonia gas and continue stirring at room temperature for 24 h; S6: Add 3 kg of citric acid to the stirred system, stir evenly, and then flash dry at 250° C. to obtain basic manganese chloride Mn2(OH)3Cl.

[0034] The basic manganese chloride obtained in this example was tested by particle size analysis to obtain D 50 The particle size is about 6 μm, D 90The particle size is less than 13μm; scanning electron microscopy analysis shows that the primary grain size is about 70nm, and composition analysis shows that the Mn element content is 54.7wt%, the Cl element content is 18.4wt%, the free water content is 4wt%, the Ca element content is 0.05wt%, the Se element content is 0.0003wt%, the P element content is 0.0001wt%, the Zn element content is 0.0017wt%, the Cr element content is 0.00002wt%, the Pb element content is 0.00003wt%, the Cd element content is 0.000007wt%, the As element content is 0.000005wt%, and the Hg element content is 0.000002wt%; XRD analysis shows that it does not contain KMnO4, MnO2, Mn3O4 and other phases.

[0035] Example 2 A composite basic manganese chloride is prepared by the following steps: (1) Add 500 kg of industrial grade manganese carbonate (98% purity) into a glass fiber reinforced plastic storage tank (3 m3) containing 1 t of water and 1.05 t of 30 wt% hydrochloric acid. 3 ), stirring until the reaction completely stops producing bubbles, and analyzing the impurity ion content in the obtained solution, as follows: Ca 2+ :1.1g / L; Zn 2+ :0.12g / L;Cu 2+ :0.004g / L;Fe 3+ :0.02g / L;Al 3+ :0.02g / L; Sb 3+ :0.002g / L; Cr 3+ :0.003g / L; As 3+ :0.003g / L; Pb 2+ :0.003g / L; Cd 2+ :0.015g / L; Hg 2+ :<0.001g / L; SO4 2- :0.55g / L;pH 3.0~3.5; S2: Adjust the pH value of the solution to 6.3, then add ultrafine manganese powder 1.5 times the total amount of iron, aluminum, copper, antimony, chromium, arsenic, lead, cadmium and mercury detected in the solution under stirring, stir for 2 hours and filter; repeat the above operation several times until Fe in the solution is reduced to 0. 3+ 、Al 3+ , Cu 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+, Hg 2+ All less than 0.002g / L; S3: Add manganese oxalate to the filtrate after filtration in S2, and the material-liquid ratio of manganese carbonate added to the filtrate is 5kg:1m 3 , stirred for 1 hour and filtered; S4: Add the Zn detected in the solution to the filtrate obtained in S3 2+ Add 1.5 times the amount of ammonium sulfide as the total amount of heavy metal ions, continue stirring for 1.5 hours, then filter and set aside; S5: Add 0.75 kg of commercially available manganese methionine microcrystals as crystal nuclei to the filtrate obtained in S4; adjust the pH value of the system to 6.5, then introduce ammonia gas under stirring, monitor the growth process of the precipitated particles in the system, and when the precipitated particles D 50 When the particle size reached 7.5 μm, stop passing ammonia gas and continue stirring at 55 °C for 10 h; S6: Add 2.3 kg of ascorbic acid to the stirred system, stir evenly, and then flash dry at 250° C. to obtain basic manganese chloride Mn2(OH)3Cl.

[0036] The basic manganese chloride obtained in this example was tested by particle size analysis to obtain D 50 The particle size is about 7.5 μm, D 90 The particle size is less than 14μm; scanning electron microscopy analysis shows that the primary grain size is about 83nm, and composition analysis shows that the Mn element content is 54.3wt%, the Cl element content is 18.1wt%, the free water content is 4.1wt%, the Ca element content is 0.01wt%, the Se element content is 0.0001wt%, the P element content is 0.0001wt%, the Zn element content is 0.0018wt%, the Cr element content is 0.000018wt%, the Pb element content is 0.000023wt%, the Cd element content is 0.0000065wt%, the As element content is 0.000005wt%, and the Hg element content is 0.0000018wt%; XRD analysis shows that it does not contain KMnO4, MnO2, Mn3O4 and other phases.

[0037] Comparative Example 1 A composite basic manganese chloride is prepared by the following steps: (1) Add 500 kg of industrial grade crude manganese chloride (MnCl2·4H2O) (purity 95%) into a glass fiber reinforced plastic storage tank (volume 3m 3 ), stirred to completely dissolve, and the impurity ion content in the obtained solution was analyzed and tested, as follows: Ca 2+ :0.6g / L; Zn 2+ :0.2g / L;Cu2+ :0.03g / L;Fe 3+ :0.02g / L;Al 3+ :0.06g / L; Sb 3+ :0.005g / L; Cr 3+ :0.005g / L; As 3+ :0.005g / L; Pb 2+ :0.005g / L; Cd 2+ :0.015g / L; Hg 2+ <0.001g / L;pH 4.0~4.5; S2: Adjust the pH value of the solution to 6.3, then add ultrafine manganese powder 1.5 times the total amount of iron, aluminum, copper, antimony, chromium, arsenic, lead, cadmium and mercury detected in the solution under stirring, stir for 1 hour and filter; repeat the above operation several times until Fe in the solution is reduced to 0. 3+ 、Al 3+ , Cu 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+ , Hg 2+ All less than 0.002g / L; S3: Add manganese carbonate to the filtrate after filtration in S2, and the material-liquid ratio of the added manganese carbonate to the filtrate is 5kg:1m 3 , stirred for 1 hour and filtered; S4: Add the Zn detected in the solution to the filtrate obtained in S3 2+ Add 1.5 times the amount of ammonium sulfide as the total amount of heavy metal ions, continue stirring for 1 hour, then filter and set aside; S5: Pass 81m3 of filtrate from S4 under stirring 3 Ammonia, and then continue stirring at room temperature for 24h; S6: flash drying the stirred system at 250° C. to obtain basic manganese chloride Mn2(OH)3Cl.

[0038] In this comparative example, no nucleating agent and surface modifier were added, and the obtained basic manganese chloride was tested by particle size analysis to obtain D 50 The particle size is about 18 μm, D 90 The particle size is 35μm; scanning electron microscopy analysis shows that the primary grain size is about 310nm, and composition analysis shows that the Mn element content is 56.3wt%, the Cl element content is 16.7wt%, and the free water content is 6.2wt%; XRD analysis shows that about 19.0wt% of the phases are MnO2, Mn3O4, etc.

[0039] Comparative Example 2 A composite basic manganese chloride is prepared by the following steps: (1) Add 500 kg of industrial grade manganese carbonate (98% purity) into a glass fiber reinforced plastic storage tank (3 m3) containing 1 t of water and 1.05 t of 30 wt% hydrochloric acid. 3 ), stirring until the reaction completely stops producing bubbles, and analyzing the impurity ion content in the obtained solution, as follows: Ca 2+ :1.1g / L; Zn 2+ :0.12g / L;Cu 2+ :0.004g / L;Fe 3+ :0.02g / L;Al 3+ :0.02g / L; Sb 3+ :0.002g / L; Cr 3+ :0.003g / L; As 3+ :0.003g / L; Pb 2+ :0.003g / L; Cd 2+ :0.015g / L; Hg 2+ :<0.001g / L; SO4 2- :0.55g / L;pH 3.0~3.5; S2: Adjust the pH value of the solution to 6.3, then add ultrafine manganese powder 1.5 times the total amount of iron, aluminum, copper, antimony, chromium, arsenic, lead, cadmium and mercury detected in the solution under stirring, stir for 2 hours and filter; repeat the above operation several times until Fe in the solution is reduced to 0. 3+ 、Al 3+ , Cu 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+ , Hg 2+ All less than 0.002g / L; S3: Add manganese oxalate to the filtrate after filtration in S2, and the material-liquid ratio of manganese carbonate added to the filtrate is 5kg:1m 3 , stirred for 1 hour and filtered; S4: Add the Zn detected in the solution to the filtrate obtained in S3 2+ Add 1.5 times the amount of ammonium sulfide as the total amount of heavy metal ions, continue stirring for 1.5 hours, then filter and set aside; S5: Pass 81m3 of filtrate from S4 under stirring 3 ammonia, and then continue stirring at 55 °C for 10 h; S6: flash drying the stirred system at 250° C. to obtain basic manganese chloride Mn2(OH)3Cl.

[0040] In this comparative example, no nucleating agent and surface modifier were added, and the obtained basic manganese chloride was tested by particle size analysis to obtain D 50 The particle size is about 22 μm, D 90 The particle size is about 43μm; scanning electron microscopy analysis shows that the primary grain size is about 330nm; composition analysis shows that the Mn element content is 55.4wt%, the Cl element content is 17.1wt%, and the free water content is 7.1wt%; XRD analysis shows that about 12.9wt% of the phases are MnO2, Mn3O4, etc.

[0041] By comparing the embodiment with the comparative example, it can be seen that the present invention can effectively remove harmful ions in the reaction system by adding metallic manganese and an impurity remover to the reaction system, and the final product will not have an adverse effect on animals and plants; and in the preparation process, a crystal nucleating agent and a surfactant are also added to the system; wherein the crystal nucleating agent can well control the agglomeration phenomenon in the reaction system and can promote the forward reaction, thereby making the yield of the target product higher and the particles of the target product more uniform, thereby obtaining a basic manganese chloride product with a narrow and uniform particle size distribution range; in addition, the addition of the crystal nucleating agent can also introduce specific nutrients into the basic manganese chloride product, making it easier for animals and plants to absorb and utilize, so that the obtained product can be better used as feed or plant fertilizer; the surfactant can not only prevent the uncontrollable agglomeration between the Mn2(OH)3Cl grains obtained by the reaction, but also prevent the oxidation of Mn2(OH)3Cl by oxygen in the air during the drying process, thereby producing Mn 3+ , Mn 4+ The composite basic manganese chloride prepared by the present invention has a very low harmful ion content and does not contain high-valent manganese, and can be used as an additive for animal feed and plant fertilizer.

[0042] Although the specific implementation of the present invention is described in detail in conjunction with the embodiments, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A method for preparing a composite basic manganese chloride, characterized in that: The following steps are involved: S1: dissolving the manganese-containing material in water or acid solution to prepare a solution with a manganese ion concentration of 75-130 g / L; S2: Adjust the solution to weak acidity, then add metallic manganese to the solution, stir, filter, and repeat the above steps several times until Fe 3+ 、Al 3+ , Cu 2+ , Sb 3+ Cr 3+ 、As 3+ , Pb 2+ 、Cd 2+ , Hg 2+ All less than 0.002g / L; S3: adding an impurity remover to the filtrate obtained in S2, stirring and filtering, then adding ammonium sulfide to the filtrate, continuing to stir and filter, to obtain a pure manganese solution; S4: Add a crystal nucleation agent to the pure manganese solution, adjust the pH of the pure manganese solution to 6-7, and then introduce a precipitant into the pure manganese solution for precipitation reaction until the D of the precipitated particles reaches 50 When the particle size reaches 6-8 μm, stop the precipitation reaction and stir at 20-55 °C for 10-24 h; S5: Add the surface modifier to the system obtained in S4, mix well and then flash dry at 250°C to obtain.

2. The preparation method according to claim 1, characterized in that: The manganese-containing material is industrial manganese chloride, industrial manganese carbonate or industrial manganese oxide; and the acid solution is hydrochloric acid solution.

3. The preparation method according to claim 1, characterized in that: The solution in S2 is adjusted to a weakly acidic pH of 6-6.5; the metallic manganese is ultrafine manganese powder, manganese particles, manganese blocks or manganese ingots; the amount of metallic manganese added is 1.5 times the total amount of iron, aluminum, copper, antimony, chromium, arsenic, lead, cadmium and mercury detected in the solution.

4. The preparation method according to claim 1, characterized in that: The impurity remover is at least one of manganese sulfide, manganese oxalate, manganese carbonate, manganese selenide, ammonium bicarbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium oxalate, potassium oxalate, sodium silicate, potassium silicate, sodium selenate, potassium selenate, sodium phosphate, potassium phosphate and lithium phosphate; the material-liquid ratio of the added impurity remover to the filtrate is 5kg:1m 3 The stirring time after adding the impurity remover is 1h; the amount of ammonium sulfide added is 1.5 times the zinc detected in the solution, and the stirring time after adding ammonium sulfide is 1~2h.

5. The preparation method according to claim 1, characterized in that: The crystal nucleus agent is at least one of selenoamino acid manganese, methionine manganese, manganese oxalate, manganese citrate, manganese gluconate, methionine manganese and manganese proteinate.

6. The preparation method according to claim 5, characterized in that: The mass ratio of the added nucleating agent to the manganese-containing material is 0.5~1:

500.

7. The preparation method according to claim 6, characterized in that: The precipitant is at least one of ammonia gas, liquid ammonia, ammonia water, sodium hydroxide, potassium hydroxide and lithium hydroxide.

8. The preparation method according to claim 7, characterized in that: The surface modifier is at least one of glucose, sucrose, citric acid, ascorbic acid, amino acids, unsaturated fatty acids, salicylic acid, ethylene glycol, glycerol, ethyl acetate and butanone; the mass ratio of the added surface modifier to the crystal nucleating agent is 3-3.1:

1.

9. A composite basic manganese chloride, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8; the composite basic manganese chloride D 50 Particle size is 5~10μm, D 90 The particle size is less than 15μm, the Mn element content is 53.0wt%~56.8wt%, the Cl element content is 16.5wt%~19.5wt%, the H2O content is 1wt~5wt%, the Ca element content is 0.01wt%~0.05wt%, the Se element content is 0.0001wt%~0.0005wt%, the P element content is 0.0001wt%~0.0003wt%, the Zn element content is 0.0015wt%~0.002wt%, and the Cr, Pb, Cd, As and Hg element contents are all less than 0.00003wt%.

10. The use of the composite basic manganese chloride according to claim 9, characterized in that: The composite basic manganese chloride is used as an animal feed additive or a plant fertilizer additive.