Co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine

Abstract

The present invention relates to the technical field of feed additives, and particularly to a co-production preparation method of calcium hydroxy methionine and trace element chelated hydroxy methionine. Hydroxy methionine is added to a calcium hydroxide emulsion, the reaction temperature is 70-100 °C, the reaction pH is 6.5-8.0, the reaction time is 30-120 min. After the reaction, the temperature is lowered and filtered to obtain wet calcium hydroxy methionine and the mother liquor of calcium hydroxy methionine crystals; the mother liquor of calcium hydroxy methionine crystals is heated to 50-80 °C, then a trace element metal salt is added, and the reaction is carried out at 60-80 °C with heat preservation and stirring for 60-150 min. During the reaction process, calcium oxide or calcium hydroxide is used to control the pH at 6.5-7.5, and after cooling and filtering, the obtained wet product of trace element chelated hydroxy methionine is dried at 100-110 °C to obtain the product of trace element chelated hydroxy methionine. The present invention can maximize the utilization of the mother liquor of calcium hydroxy methionine crystals to produce the product of trace element chelated hydroxy methionine, and the raw material hydroxy methionine can achieve the maximum utilization rate, with the utilization rate reaching more than 99%.

Description

Technical Field

[0001] The present invention relates to the technical field of feed additives, and particularly to a co-production preparation method of calcium hydroxy methionine and trace element chelated hydroxy methionine. Background Art

[0002] L-2-hydroxy-4-methylthio butyric acid is also known as methionine hydroxy analog (MHA) or hydroxy methionine, and is mainly used as a feed additive to supplement methionine. As early as the 1950s, MHA has been applied in the livestock industry, and it has been confirmed by the feed industry, livestock industry and pet production enterprises that MHA is an excellent methionine source. Although MHA has many advantages, there are also: 1) It has strong corrosiveness and pungent smell, which is inconvenient for storage, transportation and use, and a special liquid feeding system with high price must be used; 2) It has high viscosity and is not easy to mix evenly in feed premixes; 3) It releases a large amount of heat when encountering water, causing the feed to heat up, ferment and go rancid during storage and transportation; 4) It has high acidity, with a pH of about 1, and is easy to react with other components in the feed or premixed feed by acid-base reaction, damaging the nutritional components in the feed, etc.

[0003] In the prior art, the above problems are generally solved by reacting with calcium salt to generate hydroxymethionine calcium salt or adsorbing and drying with an inert carrier to achieve solidification and dispersion. At present, there are two main methods for industrial production of hydroxymethionine calcium salt: one is a dry mixing method, that is, commercial-grade hydroxymethionine is directly mixed and stirred with calcium oxide or calcium hydroxide, and then dried, crushed, sieved, etc. to obtain a powdered hydroxymethionine calcium salt product. Chinese patent CN104356035A discloses that hydroxymethionine and one or more of calcium hydroxide, calcium oxide, and calcium carbonate are used as reaction raw materials, and ammonium bisulfate is introduced as a reaction catalyst to react to obtain a hydroxymethionine calcium salt product. In the patent document of publication number CN 102675171 A, calcium hydroxide or calcium oxide, calcium carbonate is added to a mixing dryer, followed by continuous addition of hydroxymethionine solution, or calcium hydroxide or calcium oxide, calcium carbonate and hydroxymethionine solution are added simultaneously, stirred and reacted, the material is kept at a vaporization temperature of 100 degrees or more, after the reaction is completed, it is continuously dried for 35 to 40 minutes, and finally cooled, crushed and sieved to obtain hydroxymethionine calcium salt. The above methods all use hydroxymethionine to directly react with calcium sources such as calcium hydroxide and calcium carbonate to prepare solid methionine hydroxy analog calcium salt to achieve the solidification of liquid hydroxymethionine, and have the advantage of providing calcium element at the same time, but because the currently commercially available hydroxymethionine contains more dimers and oligomers, it is difficult to fully react and adsorb on the calcium salt to make the product sticky and difficult to dry, and the neutralization reaction with calcium hydroxide and the like is violently exothermic, which is easy to cause local overheating and incomplete reaction, so it is easy to obtain local coking, agglomeration, and poor fluidity of solid hydroxymethionine calcium salt. The advantages of the above method are simplicity and the absence of mother liquor. The disadvantages are insufficient reaction, especially the inability to completely hydrolyze dimers and polymers in hydroxymethionine. The product is in the form of fine powder with a particle size of 25 to 50 μm, poor fluidity, easy agglomeration, and a bulk density of only 0.29 g / mL. The quality requirements of the raw material calcium oxide or calcium hydroxide are very high. Not only is the particle size requirement of calcium oxide or calcium hydroxide high (25 to 38 μm), but other impurities in the calcium source such as iron, magnesium, aluminum, and heavy metals are also relatively strict. The purity of calcium oxide or calcium hydroxide must basically reach the level of analytical purity, which will undoubtedly increase the production cost. The product has a strong smell and is heavily polluted by dust during product packaging. In order to solve the dust pollution during packaging, it is necessary to spray mineral oil of about 1% of the product weight into the product.

[0004] Another method for industrially producing calcium hydroxymethionine is the aqueous phase method, that is, using water as the reaction solvent, diluting commercial grade hydroxymethionine to a certain concentration, and then adding calcium oxide or calcium hydroxide for neutralization reaction. Then, the temperature is lowered for crystallization, and the wet product of calcium hydroxymethionine precipitated is filtered out and dried to obtain the hydroxymethionine product. Or, calcium oxide is added to water to prepare a calcium hydroxide emulsion with a certain concentration, and then hydroxymethionine is added for neutralization reaction. Then, the temperature is lowered for crystallization, and the wet product of calcium hydroxymethionine precipitated is filtered out and dried to obtain the hydroxymethionine product. The advantages of the aqueous phase method are: the quality requirements for the calcium source are not very high, and ordinary industrial grade calcium oxide or calcium hydroxide is sufficient; the obtained product is spherical, has good fluidity, high bulk density (0.4 - 0.55 g / mL), small odor, is not easy to caking, has little dust pollution during packaging, and there is no need to add mineral oil to the product for dust reduction treatment. The disadvantages are: the product yield is relatively low, generally only 80% - 90%, and 10% - 20% of calcium hydroxymethionine remains in the mother liquor. In order to obtain a higher yield of calcium hydroxymethionine, the recycling of the mother liquor needs to be considered. The problem brought about by this is that the impurities in the raw materials calcium oxide or calcium hydroxide and hydroxymethionine basically remain in the mother liquor. With the recycling of the mother liquor, the problems of impurity accumulation and the impact on the crystallization of calcium hydroxymethionine and the quality of the product are brought about. To solve the problem of mother liquor recycling, usually when the mother liquor is recycled to a certain number of times and cannot be recycled, a part of the mother liquor is taken out for incineration treatment. However, such a treatment method will inevitably cause the loss of hydroxymethionine and consume a large amount of energy, ultimately resulting in an increase in the production cost of calcium hydroxymethionine. For example, in the patent with publication number CN103467348A, it is disclosed that using 2-hydroxy-4-methylthiobutyric acid, calcium compound and crystallization agent as raw materials, in an aqueous medium, the pH is adjusted to 5 - 7, the temperature is 60 - 80 °C, and after sufficient stirring and reaction, it is cooled and crystallized to obtain 2-hydroxy-4-methylthiobutyric acid calcium crystals, and the crystals and the crude mother liquor are separated. The crystallization is the crude product of calcium hydroxymethionine; the calcium compound is one or more of calcium salt, calcium oxide and calcium hydroxide; the dosage of the crystallization agent is 50 ppm - 3000 ppm of the mass of hydroxymethionine. The materials produced by this method have high purity, but due to the need for recrystallization and dehydration again, the process is relatively complex. In actual production of the existing disclosed methods, there are problems such as the synthesized calcium hydroxymethionine having high viscosity, low density, and poor fluidity, so it is difficult to be fully mixed with the feed, the feed quality is unstable, and thus the feeding effect is affected.

[0005] The current main production methods of hydroxy methionine chelated trace elements are as follows: using hydroxy methionine, trace element metal sulfate, sodium hydroxide or potassium hydroxide as raw materials. First, hydroxy methionine reacts with an equimolar amount of sodium hydroxide or potassium hydroxide aqueous solution for a neutralization reaction to produce an aqueous solution of sodium (or potassium) hydroxy methionate. Then, the aqueous solution of sodium (or potassium) hydroxy methionate is mixed and reacted with the aqueous solution of trace element metal sulfate to obtain a hydroxy methionine chelated trace element precipitate. This process method can obtain hydroxy methionine chelate with relatively high purity, solve the influence of dimers and polymers in hydroxy methionine on the reaction, and hydroxy methionine and metal ions can be fed according to the theoretical ratio. However, the biggest problem is that it consumes a large amount of alkali such as sodium hydroxide and potassium hydroxide, and by-produces inorganic salts such as sodium sulfate, sodium chloride, potassium sulfate or potassium chloride. The yield of hydroxy methionine chelate is 80% - 95%. The product is in powder form, with a small bulk density and easy to agglomerate. For example, in patent CN1287795, liquid hydroxy methionine reacts with an aqueous solution of an inorganic salt of zinc in a molar ratio of 1:1 - 2 at a temperature of 50 - 100 °C, a pH value of 6 - 8, and under normal pressure conditions for 0.8 - 1.2 hours for chelation. For instance, patent CN103254104A discloses a preparation method of a trace element methionine hydroxy analogue chelate. The method includes the following steps: 1) separately input the methionine hydroxy analogue solution and the mixed solution of water or an organic substance and water into a closed reaction kettle protected by an inert gas, start stirring for a hydrolysis reaction, then add an alkaline solution, and control the pH value at the end of the reaction; 2) add a basic salt, acid salt or amphoteric salt of a trace metal element to the liquid obtained from the reaction in step 1) and continue the reaction, and control the pH value at the end of the reaction to be 5 - 8 to obtain a liquid containing a trace element methionine hydroxy analogue chelate; 3) dehydrate, dry and screen the liquid obtained after the reaction in step 2) to obtain a trace element methionine hydroxy analogue chelate.

[0006] Therefore, it has very important practical significance in this field to research and develop a method that can simultaneously produce calcium hydroxy methionate using hydroxy methionine as the main raw material, solve the problem of difficult treatment of the crystallization mother liquor of calcium hydroxy methionate, recover valuable hydroxy methionine as much as possible, and effectively solve the influence of dimers and polymers of the raw material hydroxy methionine on the reaction during the production process. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a co-production preparation method of calcium hydroxy methionate and hydroxy methionine chelated trace elements, so as to at least solve the problems existing in the prior art, such as the difficult treatment of the crystallization mother liquor of calcium hydroxy methionate, the adverse influence of dimers and polymers in the raw material hydroxy methionine on the reaction during the production process, and the problem of difficult recycling of hydroxy methionine.

[0008] The present invention solves the above technical problems through the following technical means:

[0009] The present invention provides a co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine, comprising the following steps:

[0010] Add hydroxymethionine to the calcium hydroxide emulsion and stir. Set the reaction temperature at 70 - 100°C, the reaction pH at 6.5 - 8.0, and the reaction time at 30 - 120 min. After the reaction, cool down and filter to obtain the wet product of calcium hydroxymethionine and the crystallization mother liquor of calcium hydroxymethionine;

[0011] Heat the crystallization mother liquor of calcium hydroxymethionine to 50 - 80°C, then add the trace element metal salt, and carry out a heat preservation stirring reaction at 60 - 80°C for 60 - 150 min. During the reaction process, use calcium oxide or calcium hydroxide to control the pH at 6.5 - 7.5. Cool down and filter to obtain the wet product of trace element chelated hydroxymethionine, and dry it at 100 - 120°C to obtain the product of trace element chelated hydroxymethionine.

[0012] In some embodiments, the calcium hydroxide emulsion is prepared by adding calcium oxide to water and stirring. The preheating temperature of the calcium hydroxide emulsion is 65 - 70°C, and the molar ratio of calcium oxide to water for feeding is 1:27.3 - 67.7.

[0013] In some embodiments, the content of effective calcium in the calcium oxide is ≥70.0 wt%, arsenic ≤5 ppm, lead ≤20 ppm, cadmium ≤5 ppm, and the passing rate through a 200 - mesh sieve is ≥90%.

[0014] In some embodiments, the molar ratio of calcium in the calcium hydroxide emulsion to hydroxymethionine for feeding is 1.90 - 2.10:0.98 - 1.10.

[0015] In some embodiments, the hydroxymethionine is of commercial grade, with a percentage content of 88 wt%, containing 65 wt% of hydroxymethionine monomer, 23 wt% of dimer and polymer, 10 wt% - 12 wt% of water, and 0.5 wt% - 2.0 wt% of ammonium sulfate.

[0016] In some embodiments, the pH value of the crystallization mother liquor of calcium hydroxymethionine is 6.5 - 8.0, and the percentage content of calcium hydroxymethionine is 5.0 wt% - 15.0 wt%.

[0017] In some embodiments, the dosage of the trace element metal salt is 1.0 - 1.1 times or 2.0 - 2.1 times the molar amount of calcium hydroxymethionine in the crystallization mother liquor of calcium hydroxymethionine.

[0018] In some embodiments, the trace element metal salt is a chloride or acetate of divalent zinc ion, divalent copper ion, divalent manganese ion, ferrous ion, divalent nickel ion, divalent cobalt ion, and trivalent chromium ion, preferably a chloride. Reacting the chloride with the mother liquor of hydroxy methionine calcium salt to generate a reaction solution containing hydroxy methionine chelated trace elements. Calcium chloride in the reaction solution can affect the crystal form of hydroxy methionine chelated trace elements, effectively improving the product appearance of hydroxy methionine chelated trace elements, and obtaining hydroxy methionine chelated trace elements that are uniform in size and similar to spherical shape. And because hydroxy methionine chelated trace elements may carry by-products such as calcium chloride during the crystallization process, the presence of a small amount of calcium chloride can improve the fluidity of the hydroxy methionine chelated trace element product and reduce caking.

[0019] In some embodiments, the molar ratio of hydroxy methionine to metal ion in the hydroxy methionine chelated trace element product is 1:1 or 2:1. The hydroxy methionine chelated trace element product is spherical with a particle size of 350 - 700 μm, and the main content of hydroxy methionine chelated trace elements is ≥ 97 wt%, arsenic ≤ 1 ppm, lead ≤ 5 ppm, and there is no cadmium.

[0020] In some embodiments, the wet product of hydroxy methionine calcium salt is dried at a temperature of 105 - 120 °C. The obtained hydroxy methionine calcium salt is spherical with a particle size of 150 - 500 μm, the main content of hydroxy methionine calcium is ≥ 96 wt%, and there is no arsenic, no lead, and no cadmium.

[0021] The co-production preparation method of hydroxy methionine calcium salt and hydroxy methionine chelated trace elements of the present invention uses the calcium hydroxide emulsion prepared by reacting calcium oxide and water to react with hydroxy methionine to generate hydroxy methionine calcium salt, and uses the mother liquor generated during the production process of hydroxy methionine calcium salt to react with the trace element metal salt to generate hydroxy methionine chelated trace elements. It can maximize the utilization of the mother liquor of hydroxy methionine calcium salt to produce hydroxy methionine chelated trace element products, and the raw material hydroxy methionine can reach the maximum utilization rate, with the utilization rate reaching more than 99%. It not only solves the problem of difficult treatment of the traditional mother liquor of hydroxy methionine calcium salt and the high quality requirement for calcium source in the dry mixing method, but also obtains hydroxy methionine calcium salt and hydroxy methionine chelated trace element products with spherical shape, good fluidity, and high bulk density, avoiding the influence of dimers and polymers in the raw material hydroxy methionine on the reaction and products in the traditional process.

[0022] In the co-production preparation method of calcium hydroxy methionine and trace element chelated hydroxy methionine of the present invention, during the preparation process of trace element chelated hydroxy methionine, calcium oxide or calcium hydroxide is used to control the pH at 6.5 - 7.5. On the one hand, using calcium oxide or calcium hydroxide as the pH regulator can avoid the generation of more complex inorganic salt by-products due to the use of complex and diverse raw materials, making the inorganic salt components in the reaction solution of trace element chelated hydroxy methionine single, which is beneficial to improving the purity and quality of the trace element chelated hydroxy methionine product. On the other hand, using calcium oxide or calcium hydroxide as the pH regulator, the finally generated calcium chloride salt has a good pH buffering effect on the reaction system, preventing the pH value of the reaction system from being too high (if sodium hydroxide or potassium hydroxide is used as the pH regulator, the problems are that the pH is not easy to control, and secondly, new impurities are introduced. If ammonia is used as the regulator, the problem is that ammonia will react with copper, zinc, and iron sulfone to form stable ammonia copper ions, resulting in a low product yield). It plays a good protective role for the easily oxidized divalent iron and divalent manganese trace elements. Moreover, using calcium oxide or calcium hydroxide as the pH regulator, during the reaction process, the relatively gentle control of the pH value is beneficial to the full conversion of calcium hydroxy methionine in the mother liquor of calcium hydroxy methionine into the trace element chelated hydroxy methionine product, effectively utilizing the calcium hydroxy methionine in the crystallization mother liquor of calcium hydroxy methionine and effectively improving the yield of the trace element chelated hydroxy methionine product.

[0023] The co-production preparation method of calcium hydroxy methionine and trace element chelated hydroxy methionine of the present invention can effectively solve the problems of the recycling of calcium hydroxy methionine in the crystallization mother liquor during the production process of calcium hydroxy methionine by the aqueous phase method, as well as the accumulation of impurities and heavy metals in the mother liquor. The process is simple, the operation is convenient, the cost is low, the product is safe, the production equipment is simple, and the investment is small, which is suitable for large-scale production. Brief Description of the Drawings

[0024] Figure 1 It is a process schematic diagram of the co-production preparation method of calcium hydroxy methionine and trace element chelated hydroxy methionine of the present invention. Detailed Embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] For those not specified in the following embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For the raw materials, equipment or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0027] The co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine of the present invention uses the calcium hydroxide emulsion prepared by mixing calcium oxide and water to react with hydroxymethionine to produce calcium hydroxymethionine, and uses the crystallization mother liquor generated during the production process of calcium hydroxymethionine to react with trace element metal salts to produce trace element chelated hydroxymethionine. It can maximize the utilization of the calcium hydroxymethionine crystallization mother liquor to produce trace element chelated hydroxymethionine products, and the raw material hydroxymethionine can achieve the maximum utilization rate, with the utilization rate reaching more than 99%. It not only solves the problem that the traditional calcium hydroxymethionine mother liquor is difficult to handle and the high quality requirement for calcium source in the dry mixing method, but also obtains calcium hydroxymethionine and trace element chelated hydroxymethionine products with spherical shape, good fluidity and high bulk density, avoiding the influence of dimers and polymers in the raw material hydroxymethionine on the reaction and products in the traditional process.

[0028] Specifically, the co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine of the present invention includes the following steps:

[0029] Add hydroxymethionine to the calcium hydroxide emulsion and stir. Set the reaction temperature at 70-100°C, the reaction pH at 6.5-8.0, and the reaction time at 30-120 min. After the reaction, cool down and filter to obtain wet calcium hydroxymethionine and calcium hydroxymethionine crystallization mother liquor. Among them, the calcium hydroxide emulsion is prepared by adding calcium oxide to water and stirring. The preheating temperature of the calcium hydroxide emulsion is 65-70°C, the feeding molar ratio of calcium oxide to water is 1:27.3-67.7, the content of effective calcium in the calcium oxide is ≥70.0 wt%, arsenic ≤5 ppm, lead ≤20 ppm, cadmium ≤5 ppm, and the passing rate through a 200-mesh sieve is ≥90%. The feeding molar ratio of calcium in the calcium hydroxide emulsion to hydroxymethionine is 1.90-2.10:0.98-1.10. The pH value of the calcium hydroxymethionine crystallization mother liquor is 6.5-8.0, and the percentage content of calcium hydroxymethionine is 5.0 wt%-15.0 wt%.

[0030] Heat the mother liquor of calcium hydroxy methionine to 50 - 80°C, then add trace element metal salts, and carry out a holding and stirring reaction at 60 - 80°C for 60 - 150 min. During the reaction process, use calcium oxide or calcium hydroxide to control the pH at 6.5 - 7.5. Cool down and filter to obtain the wet product of hydroxy methionine chelated trace elements, and dry it at 100 - 120°C to obtain the hydroxy methionine chelated trace element product. The dosage of the trace element metal salts is 1.0 - 1.1 times or 2.0 - 2.1 times the molar amount of calcium hydroxy methionine in the mother liquor of calcium hydroxy methionine. The trace element metal salts are chlorides or acetates of divalent zinc ions, divalent copper ions, divalent manganese ions, ferrous ions, divalent nickel ions, divalent cobalt ions, and trivalent chromium ions. The wet product of calcium hydroxy methionine is dried at a temperature of 105 - 120°C. The obtained calcium hydroxy methionine is spherical with a particle size of 150 - 500 μm, and the main content of calcium hydroxy methionine is ≥ 96 wt%, without arsenic, lead, or cadmium. The molar ratio of hydroxy methionine to metal ions in the obtained hydroxy methionine chelated trace element product is 1:1 or 2:1. The hydroxy methionine chelated trace element product is spherical with a particle size of 350 - 700 μm, and the main content of the hydroxy methionine chelated trace element is ≥ 97 wt%, arsenic ≤ 1 ppm, lead ≤ 5 ppm, without cadmium.

[0031] Please refer to Figure 1 , the co - production preparation method of calcium hydroxy methionine and hydroxy methionine chelated trace elements of the present invention is carried out based on the following co - production system. This co - production system includes two parts: one part is the calcium hydroxy methionine production system, which includes a calcium oxide feeding reaction kettle, a crystallization kettle I, a hydroxy methionine storage tank, a metering pump, a plate - and - frame filter press, a mother liquor storage tank I, a flash drying system, a storage tank, a packaging machine, and a drying tail gas incineration system; the other part is the hydroxy methionine chelated trace element product production system, which includes a chelation reaction kettle, a crystallization kettle II, a plate - and - frame filter press, a mother liquor storage tank II, a flash drying system, a storage tank, a packaging machine, and a drying tail gas incineration system; the plate - and - frame filter presses, flash drying systems, packaging machines, and drying tail gas incineration systems in the above two systems can be shared or used separately.

[0032] In the production system of calcium hydroxy methionine, the oxidation and calcification material reaction kettle can be used as both the calcium oxide hydration kettle and the reaction kettle for calcium hydroxide and hydroxy methionine. The kettle bodies of the material reaction kettle and the crystallization kettle I are made of stainless steel 304 or 316L, preferably 316L. This kettle is connected to the hydroxy methionine storage tank through a metering pump. The outlet of the material reaction kettle is connected to the inlet of the crystallization kettle I. The outlet of the crystallization kettle I is connected to the inlet of the plate and frame filter press. The outlet of the plate and frame filter press is respectively connected to the inlet of the flash drying system and the mother liquor storage tank I. There is a storage tank connected between the packaging machine and the flash drying system. The inlet of the storage tank is connected to the outlet of the flash drying system, and the outlet of the storage tank is connected to the packaging machine; in the production system of hydroxy methionine chelated trace element products, both the chelation reaction kettle and the crystallization kettle II are made of stainless steel lined with enamel or Teflon materials. The inlet of the chelation reaction kettle is connected to the outlet of the mother liquor storage tank I. The outlet of the chelation reaction is connected to the inlet of the crystallization kettle II. The outlet of the crystallization kettle II is connected to the inlet of the plate and frame filter press. The outlet of the plate and frame filter press is respectively connected to the inlet of the flash drying system and the mother liquor storage tank II. There is a storage tank between the packaging machine and the flash drying system. The inlet of the storage tank is connected to the outlet of the flash drying, and the outlet of the storage tank is connected to the packaging machine.

[0033] The co-production preparation method of calcium hydroxy methionine and hydroxy methionine chelated trace elements of the present invention is referred to the following examples:

[0034] Example 1

[0035] Add 0.568 tons of calcium oxide powder with a mass percentage content of 78.9 wt% (the fineness passes through a 200-mesh sieve ≥ 90.5%, the lead content is 10 ppm, the arsenic content is 1 ppm, and the cadmium content is 1 ppm) into the material reaction kettle made of 304. Then add 5.852 tons of soft water, start stirring, and preheat to a temperature of 65 °C to obtain a milky white calcium hydroxide aqueous solution.

[0036] The 88 wt% methionine hydroxy analog (MHA) in the methionine hydroxy analog storage tank is slowly added dropwise into the above-mentioned reactor through a flow meter for stirring reaction. The reaction temperature is controlled not to exceed 90 °C, and the pH at the end of the reaction is 7.0. A total of 2.731 tons of methionine hydroxy analog is added. After adding the methionine hydroxy analog, it is kept warm and stirred in the reactor for 30 min, and then transferred to the crystallization kettle Ⅰ for cooling crystallization. The temperature at the end of crystallization is controlled to be 30 °C. The materials in the crystallization kettle are put into a plate and frame filter press for pressure filtration. The mother liquor obtained by pressure filtration, i.e., the methionine hydroxy analog calcium salt crystallization mother liquor, is transferred to the mother liquor storage tank Ⅰ for storage, and the temperature in the mother liquor storage tank Ⅰ is maintained at 30 - 35 °C. The volume of the mother liquor is 5.0 cubic meters, the content of methionine hydroxy analog calcium is 6.06 wt%, the pH is 7.2, and the methionine hydroxy analog calcium salt crystallization mother liquor is used for the production of subsequent methionine hydroxy analog chelated trace element products. The wet methionine hydroxy analog from the plate and frame filter press enters a flash dryer for drying. The drying air temperature of the dryer is 125 °C, and the flash drying tail gas is directly sent to an incinerator for incineration treatment. 2.450 tons of the dried methionine hydroxy analog calcium salt product is obtained and stored in a storage tank. After sampling and analysis, the content of methionine hydroxy analog calcium salt is 98.0 wt%, the content of methionine hydroxy analog is 85.2%, the calcium content is 12.8%, lead, arsenic, and cadmium are not detected, the bulk density is 0.5 g / mL, it is spherical granular, the particle size is 300 - 450 μm, and it has good fluidity. When the temperature of the methionine hydroxy analog calcium salt product in the storage tank drops to 40 °C, it is transported to a packaging machine for sub-packaging.

[0037] Transfer 5.0 cubic meters of the hydroxy methionine calcium salt crystallization mother liquor (containing 0.303 tons of hydroxy methionine calcium salt) in the above-mentioned mother liquor storage tank I into an enamel-lined chelating reactor made of carbon steel, stir and heat to 75 °C, and then add 0.155 tons of trace element metal chloride copper dichloride dihydrate to the chelating reactor. After adding the metal chloride, the pH in the reaction solution is about 7.0. Spherical granular precipitates are precipitated in the chelating reactor, and keep stirring at a constant temperature in the chelating reactor for 1.5 hours. Transfer all the reaction solution in the chelating reactor into an enamel-lined crystallization kettle II for cooling treatment, and control the end temperature at about 20 °C. Put the materials in the crystallization kettle II into a plate and frame filter press for pressure filtration. The mother liquor obtained by pressure filtration, namely the hydroxy methionine chelated trace element mother liquor, is transferred into the mother liquor storage tank II for storage, and the temperature in the mother liquor storage tank II is kept at 30-35 °C. The volume of the mother liquor is 4.7 cubic meters, in which the content of hydroxy methionine chelated copper is 0.008 wt%, and the pH is about 7.0. The wet product of hydroxy methionine chelated copper from the plate and frame filter press enters a flash dryer for drying treatment. The drying air temperature of the dryer is 120 °C, and the flash drying tail gas is directly sent into an incinerator for incineration treatment. The dried hydroxy methionine chelated copper product is stored in a storage tank. After sampling and analysis, the content of the hydroxy methionine chelated copper product is ≥97.0 wt%, in which the lead content is 2 ppm, the arsenic content is 0.2 ppm, and cadmium is not detected. The bulk density is 0.5 g / mL, spherical granular, and has good fluidity. When the temperature of the hydroxy methionine chelated copper in the storage tank drops to 40 °C, it is transported to a packaging machine for sub-packaging.

[0038] The reaction conditions of Examples 2-6 are the same as those of Example 1, except that the trace element metal chloride copper dichloride dihydrate in Example 1 is replaced with anhydrous zinc chloride, ferrous chloride tetrahydrate, manganese chloride tetrahydrate, cobalt chloride hexahydrate, and nickel chloride respectively. The production results of Examples 1-6 using trace element metal chlorides as raw materials are shown in Table 1.

[0039] Table 1

[0040]

[0041]

[0042] Example 7

[0043] Add 0.5151 tons of calcium oxide powder with a mass percentage content of 87.0 wt% (the fineness passes through a 200-mesh sieve ≥90.5%, the lead content is 6 ppm, the arsenic content is 0.5 ppm, and the cadmium content is 0.5 ppm) into a chemical material reaction kettle made of 316, and then add 5.852 tons of soft water. Start stirring and preheat to a temperature of 70 °C to obtain a milky white calcium hydroxide aqueous solution.

[0044] The 88 wt% methionine hydroxy analog (MHA) in the methionine hydroxy analog storage tank is slowly added to the above-mentioned reactor through a flow meter, and stirring reaction is carried out. The reaction temperature is controlled not to exceed 90 °C, and the pH at the end point of the reaction is 7.0. A total of 2.731 tons of methionine hydroxy analog is added. After adding the methionine hydroxy analog, it is kept warm and stirred in the reactor for 30 min, and then transferred to the crystallization kettle Ⅰ for cooling crystallization. The temperature at the end point of crystallization is controlled to be 45 °C. The materials in the crystallization kettle are put into a plate and frame filter press for pressure filtration. The mother liquor obtained by pressure filtration, namely the methionine hydroxy analog calcium salt crystallization mother liquor, is transferred to the mother liquor storage tank Ⅰ for storage, and the temperature in the mother liquor storage tank Ⅰ is kept at 45-50 °C. The volume of the mother liquor is 5.0 cubic meters, the content of methionine hydroxy analog calcium salt is 9.50 wt%, the pH is 7.4, and the methionine hydroxy analog calcium salt crystallization mother liquor is used for the production of subsequent methionine hydroxy analog chelated trace element products. The wet methionine hydroxy analog from the plate and frame filter press enters a flash dryer for drying. The drying air temperature of the dryer is 125 °C, and the flash drying tail gas is directly sent to an incinerator for incineration treatment. 2.270 tons of the dried methionine hydroxy analog calcium salt product is obtained and stored in a storage tank. After sampling and analysis, the content of methionine hydroxy analog calcium salt is 98.5 wt% (where the content of methionine hydroxy analog is 85.7%, the calcium content is 12.8%, lead, arsenic, and cadmium are not detected, the bulk density is 0.54 g / mL, spherical granular, and has good fluidity). When the temperature of the methionine hydroxy analog calcium salt product in the storage tank drops to 40 °C, it is transported to a packaging machine for sub-packaging.

[0045] Transfer 5.0 cubic meters of the calcium hydroxy methionine crystallization mother liquor (containing 0.475 tons of calcium hydroxy methionine) in the above-mentioned mother liquor storage tank I into an enamel-lined carbon steel chelating reactor, stir and heat to 65 °C, and then add trace element metal chloride copper dichloride dihydrate to the chelating reactor. After adding copper dichloride dihydrate, the pH of the reaction solution is about 7.0. Spherical granular precipitates precipitate in the chelating reactor, and keep stirring at a constant temperature in the chelating reactor for 1 hour. Transfer all the reaction solution in the chelating reactor into an enamel-lined crystallization kettle II for cooling treatment, and control the final temperature at about 20 °C. Put the materials in the crystallization kettle II into a plate and frame filter press for pressure filtration. The mother liquor obtained by pressure filtration, namely the calcium hydroxy methionine chelated trace element mother liquor, is transferred to the mother liquor storage tank II for storage, and the temperature in the mother liquor storage tank II is kept at 30-35 °C. The volume of the mother liquor is 4.6 cubic meters, and the content of calcium hydroxy methionine chelated trace elements is 0.005 wt%, and the pH is about 7.0. The wet calcium hydroxy methionine chelated copper product coming out of the plate and frame filter press enters a flash dryer for drying treatment. The drying air temperature of the dryer is 115 °C, and the flash drying tail gas directly enters an incinerator for incineration treatment. The dried calcium hydroxy methionine chelated copper product is stored in a storage tank. After sampling and analysis, the content of the calcium hydroxy methionine chelated copper product is ≥97.0 wt% (the lead content is 1 ppm, the arsenic content is 0.2 ppm, and cadmium is not detected, the bulk density is 0.45 g / mL, spherical granular, with good fluidity). When the temperature of the calcium hydroxy methionine chelated copper in the storage tank drops to 40 °C, it is transported to a packaging machine for sub-packaging.

[0046] The reaction conditions of Examples 8-12 are the same as those of Example 7, except that the trace element metal chloride copper dichloride dihydrate in Example 7 is replaced with anhydrous zinc chloride, ferrous chloride tetrahydrate, manganese chloride tetrahydrate, cobalt chloride hexahydrate, and nickel chloride respectively. The production results of Examples 7-12 using trace element metal chlorides as raw materials are shown in Table 2.

[0047] Table 2

[0048]

[0049] Example 13

[0050] Add 0.2490 tons of calcium oxide powder with a mass percentage content of 90.0 wt% (the fineness passes through a 200-mesh sieve ≥95%, the lead content is 10 ppm, the arsenic content is 5.0 ppm, and the cadmium content is 2.0 ppm) to a chemical material reaction kettle made of 316, and then add 4.711 tons of soft water. Start stirring and preheat to a temperature of 70 °C to obtain a milky white calcium hydroxide aqueous solution.

[0051] Methionine hydroxy analog (MHA) with a mass percentage of 88 wt% in the methionine hydroxy analog (MHA) storage tank was slowly added dropwise into the above-mentioned reactor through a flowmeter for stirring reaction. The reaction temperature was controlled not to exceed 70 °C, and the pH at the end of the reaction was 7.0. A total of 1.3655 tons of methionine hydroxy analog was added. After adding methionine hydroxy analog, it was kept warm and stirred in the reactor for 60 min, and then transferred to crystallizer I for cooling crystallization. The temperature at the end of crystallization was controlled to be 30 °C. The materials in the crystallizer were put into a plate and frame filter press for pressure filtration. The mother liquor of methionine hydroxy calcium salt obtained by pressure filtration was transferred to mother liquor storage tank I for storage, and the temperature in mother liquor storage tank I was maintained at 30 - 35 °C. The volume of the mother liquor was 4.242 cubic meters, and the content of methionine hydroxy calcium in it was 5.10 wt%, with a pH of 7.2. The mother liquor of methionine hydroxy calcium salt was used for the production of subsequent methionine hydroxy chelated trace element products. The wet methionine hydroxy analog product coming out of the plate and frame filter press entered a flash dryer for drying treatment. The drying air temperature of the dryer was 125 °C, and the flash drying tail gas was directly sent to an incinerator for incineration treatment. 1.1472 tons of the dried methionine hydroxy calcium salt product was stored in a storage tank. After sampling and analysis, the content of methionine hydroxy calcium salt was 99.0 wt% (where the content of methionine hydroxy analog was 86.5%, the calcium content was 12.5%, lead, arsenic, and cadmium were not detected, the bulk density was 0.55 g / mL, spherical granular, with good fluidity). When the temperature of the methionine hydroxy calcium salt product in the storage tank dropped to 40 °C, it was transported to a packaging machine for sub-packaging.

[0052] Transfer 4.242 cubic meters of the hydroxy methionine calcium salt crystallization mother liquor (containing 0.2163 tons of hydroxy methionine calcium salt) in the above-mentioned mother liquor storage tank I into an enamel-lined carbon steel chelating reactor, stir and heat to 65 °C, then add trace element metal chloride cupric chloride dihydrate to the chelating reactor. After adding cupric chloride dihydrate, the pH of the reaction solution is about 5.0. Add a little calcium oxide powder to the reactor to adjust the pH of the reaction solution in the reactor to about 7.0. Spherical granular precipitates precipitate in the chelating reactor, and keep stirring at a constant temperature in the chelating reactor for 2.5 hours. Transfer all the reaction solution in the chelating reactor into an enamel-lined crystallization kettle II for cooling treatment, and control the final temperature at about 20 °C. Put the materials in the crystallization kettle II into a plate and frame filter press for pressure filtration. The mother liquor obtained by pressure filtration, namely the hydroxy methionine chelated trace element mother liquor, is transferred to the mother liquor storage tank II for storage, and the temperature in the mother liquor storage tank II is kept at 30 - 35 °C. The volume of the mother liquor is 4.6 cubic meters, and the content of hydroxy methionine chelated copper in it is 0.005 wt%, and the pH is about 7.0. The wet product of hydroxy methionine chelated copper coming out of the plate and frame filter press enters a flash dryer for drying treatment. The drying air temperature of the dryer is 100 °C, and the flash drying tail gas directly enters an incinerator for incineration treatment. The dried hydroxy methionine chelated copper product is stored in a storage tank. After sampling and analysis, the content of the hydroxy methionine chelated copper product is ≥97.0 wt% (the lead content is 1 ppm, the arsenic content is 0.2 ppm, and cadmium is not detected, the bulk density is 0.63 g / mL, spherical granular, with good fluidity). When the temperature of the hydroxy methionine chelated copper in the storage tank drops to 40 °C, it is transported to a packaging machine for sub-packaging.

[0053] Examples 12 - 18 have the same reaction conditions as Example 13. The difference is that the trace element metal chloride cupric chloride dihydrate in Example 13 is replaced with anhydrous zinc chloride, ferrous chloride tetrahydrate, manganese chloride tetrahydrate, cobalt chloride hexahydrate, nickel chloride respectively. The production results of Examples 13 - 18 using trace element metal chlorides as raw materials are shown in Table 3.

[0054] Table 3

[0055]

[0056] Example 19

[0057] Add 0.568 tons of calcium oxide powder with a mass percentage content of 78.9 wt% (the fineness passes through a 200-mesh sieve ≥90.0%, the lead content is 15 ppm, the arsenic content is 5 ppm, and the cadmium content is 2 ppm) into a chemical material reaction kettle made of 304, then add 3.672 tons of soft water, start stirring, and preheat to a temperature of 70 °C to obtain a milky white calcium hydroxide aqueous solution.

[0058] The 88 wt% methionine hydroxy analog (MHA) in the methionine hydroxy analog storage tank was slowly added to the above-mentioned reactor through a flow meter, and stirring reaction was carried out. The reaction temperature was controlled not to exceed 90 °C, and the pH at the end of the reaction was 7.0. A total of 2.731 tons of methionine hydroxy analog was added. After adding methionine hydroxy analog, it was kept warm and stirred in the reactor for 120 min, and then transferred to the crystallization kettle Ⅰ for cooling crystallization. The temperature at the end of crystallization was controlled to be 30 °C. The materials in the crystallization kettle were put into a plate and frame filter press for pressure filtration. The mother liquor obtained by pressure filtration, namely the methionine calcium salt mother liquor, was transferred to the mother liquor storage tank Ⅰ for storage, and the temperature in the mother liquor storage tank Ⅰ was maintained at 30-35 °C. The volume of the mother liquor was 3.60 cubic meters, the content of methionine calcium in it was 7.50 wt%, the pH was 7.2, and the methionine calcium salt mother liquor was used for the production of subsequent methionine chelated trace element products. The wet methionine hydroxy analog from the plate and frame filter press entered a flash dryer for drying. The drying air temperature of the dryer was 105 °C, and the flash drying tail gas was directly sent to an incinerator for incineration treatment. 2.471 tons of the dried methionine calcium salt product was stored in a storage tank. After sampling and analysis, the content of methionine calcium salt was 98.5 wt% (where the content of methionine hydroxy analog was 85.5%, the calcium content was 13.0%, lead, arsenic and cadmium were not detected, the bulk density was 0.52 g / mL, spherical granular, with good fluidity). When the temperature of the methionine calcium salt product in the storage tank dropped to 40 °C, it was transported to a packaging machine for sub-packaging.

[0059] Transfer 3.60 cubic meters of the hydroxy methionine calcium salt crystallization mother liquor (containing 0.270 tons of hydroxy methionine calcium salt) in the above-mentioned mother liquor storage tank I into an enamel-lined carbon steel chelating reactor, stir and heat to 80 °C, then add trace element metal chloride cupric chloride dihydrate into the chelating reactor. After adding cupric chloride dihydrate, the pH of the reaction solution is about 5.0. Add a little calcium oxide powder into the reactor to adjust the pH of the reaction solution in the reactor to about 7.0. Spherical granular precipitates precipitate in the chelating reactor, and keep stirring in the chelating reactor for 2 hours. Transfer all the reaction solution in the chelating reactor into an enamel-lined crystallization kettle II for cooling treatment, and control the final temperature at about 20 °C. Put the materials in the crystallization kettle II into a plate and frame filter press for pressure filtration. The mother liquor obtained by pressure filtration, namely the hydroxy methionine chelated trace element mother liquor, is transferred into the mother liquor storage tank II for storage, and the temperature in the mother liquor storage tank II is kept at 30-35 °C. The volume of the mother liquor is 3.2 cubic meters, the content of hydroxy methionine chelated trace elements is 0.009 wt%, and the pH is about 7.0. The wet hydroxy methionine chelated copper product coming out of the plate and frame filter press enters a flash dryer for drying treatment. The drying air temperature of the dryer is 110 °C, and the flash drying tail gas is directly sent into an incinerator for incineration treatment. The dried hydroxy methionine chelated copper product is stored in a storage tank. After sampling and analysis, the content of the hydroxy methionine chelated copper product is ≥97.0 wt% (the lead content is 1 ppm, the arsenic content is 0.1 ppm, and cadmium is not detected, the bulk density is 0.4-0.6 g / mL, spherical granular, and has good fluidity). When the temperature of the hydroxy methionine chelated copper in the storage tank drops to 40 °C, it is transported to a packaging machine for sub-packaging.

[0060] The reaction conditions of Examples 21-25 are the same as those of Example 20. The difference is that the trace element metal chloride cupric chloride dihydrate in Example 19 is replaced with anhydrous zinc chloride, ferrous chloride tetrahydrate, manganese chloride tetrahydrate, cobalt chloride hexahydrate, and nickel chloride respectively. The production results of Examples 21-25 using trace element metal chlorides as raw materials are shown in Table 2.

[0061] Table 4

[0062]

[0063]

[0064] Comparative Example 1 (dry mixing method)

[0065] 0.568 tons of calcium oxide powder (fineness passing 200 mesh sieve ≥90.0%, lead content 15ppm, arsenic content 5ppm, cadmium content 2ppm) with a mass percentage of 78.9wt% and 2.731 tons of hydroxymethionine with a mass percentage of 88% were added to a reactor with a stirrer, and the mixture was fully stirred and mixed at a reaction temperature of 80-100°C to obtain an off-white paste reactant, and the paste was sent to a dryer for drying at 120°C, with the dryness loss controlled to be ≤1.0%, to obtain a block-like off-white solid. The solid was crushed and sieved to obtain 2.972 tons of gray-white fine powder hydroxymethionine calcium salt product, wherein the purity of hydroxymethionine calcium salt was 91.0% (hydroxymethionine content was 80.86%, calcium content was 10.77%), the lead content of the product was 3ppm, the arsenic content was 1ppm, the cadmium content was 0.5ppm, the pass rate of the product through a 200-mesh sieve was ≥90%, the bulk density was 0.35g / mL, the fluidity was poor, and the odor and powdery ash were strong.

[0066] Comparative Example 2 (Dry Mixing Method)

[0067] 0.4980 tons of calcium oxide powder (fineness passing 200 mesh sieve ≥90.0%, lead content 10ppm, arsenic content 3ppm, cadmium content 1ppm) with a mass percentage of 90.0wt% and 2.731 tons of hydroxymethionine with a mass percentage of 88% were added to a reactor with a stirrer, and the mixture was fully stirred and mixed at a reaction temperature of 80-100°C to obtain an off-white paste reactant, and the paste was sent to a dryer for drying at 120°C, with the dry loss controlled to be ≤1.0%, to obtain a block-like off-white solid. The solid matter was crushed and sieved to obtain 2.845 tons of gray-white fine powder hydroxymethionine calcium salt product, wherein the purity of hydroxymethionine calcium salt was 95.7% (hydroxymethionine content was 84.1%, calcium content was 11.60%), the lead content in the product was 2ppm, the arsenic content was 1ppm, the cadmium content was 0.5ppm, the pass rate of the product through a 200-mesh sieve was ≥90%, the bulk density was 0.35g / mL, the fluidity was poor, and the odor and powdery ash were strong.

[0068] Therefore, in order to obtain qualified hydroxymethionine calcium salt products, the dry mixing method needs to have relatively high quality requirements for lime, among which the calcium oxide content must be ≥90%, the lead content must be ≤10ppm, the arsenic content must be ≤5ppm, and the cadmium content must be ≤0.5ppm.

[0069] Comparative Example 3: Recycling of mother liquor from aqueous phase method

[0070] In an 8000L reactor made of 304 material, add 0.568 tons of calcium oxide powder with a mass percentage of 78.9wt% (the fineness passes through a 200-mesh sieve ≥90.5%, the lead content is 10ppm, the arsenic content is 1ppm, and the cadmium content is 1ppm). Then add 5.852 tons of soft water, start stirring, and preheat to a temperature of 65°C to obtain a milky white calcium hydroxide aqueous solution.

[0071] Slowly add hydroxy methionine (MHA) with a mass percentage of 88wt% in the hydroxy methionine (MHA) storage tank to the above-mentioned reactor through a flow meter, carry out stirring reaction, control the reaction temperature not to exceed 90°C, and the pH at the end of the reaction is 7.0. A total of 2.731 tons of hydroxy methionine is added. After adding hydroxy methionine, keep stirring in the reactor for 30 minutes, then transfer it to crystallizer I for cooling crystallization, and control the end temperature of crystallization to be 30°C. Put the materials in crystallizer I into a plate and frame filter press for pressure filtration. The mother liquor obtained by pressure filtration, namely the calcium salt mother liquor of hydroxy methionine, is transferred to mother liquor storage tank I for storage, and the temperature in mother liquor storage tank I is maintained at 30 - 35°C. The volume of the mother liquor is 5.0 cubic meters, the content of calcium salt of hydroxy methionine is 6.06wt%, and the pH is 7.2. All of this mother liquor is applied to the water for slaking lime in the production process of the next batch of calcium salt of hydroxy methionine (when recycling the mother liquor, the calcium salt of hydroxy methionine in the mother liquor needs to be deducted). The wet product of hydroxy methionine from the plate and frame filter press enters a flash dryer for drying treatment. The drying air temperature of the dryer is 125°C, and the flash drying tail gas is directly sent to an incinerator for incineration treatment. 2.450 tons of the dried calcium salt product of hydroxy methionine is stored in a storage tank. After sampling and analysis, the content of the calcium salt of hydroxy methionine is 98.0wt% (where the content of hydroxy methionine is 85.2%, the calcium content is 12.8%, lead, arsenic, and cadmium are not detected, the bulk density is 0.5g / mL, spherical granular, the particle size is 300 - 450μm, and it has good fluidity). When the temperature of the calcium salt product of hydroxy methionine in the storage tank drops to 40°C, it is transported to a packaging machine for sub-packaging.

[0072] Mother liquor recycling application:

[0073] In a reactor made of 304 material, add 0.568 tons of calcium oxide powder with a mass percentage of 78.9wt% (the fineness passes through a 200-mesh sieve ≥90.5%, the lead content is 10ppm, the arsenic content is 1ppm, and the cadmium content is 1ppm). Then add 5.0 cubic meters of mother liquor and 1.152 tons of soft water, start stirring, and preheat to a temperature of 65°C to obtain a milky white calcium hydroxide aqueous solution.

[0074] The 88 wt% methionine hydroxy analog (MHA) in the methionine hydroxy analog storage tank was slowly added dropwise into the above-mentioned reactor through a flowmeter for stirring reaction. The reaction temperature was controlled not to exceed 90 °C, and the pH at the end of the reaction was 7.0. A total of 2.731 tons of methionine hydroxy analog was added. After adding the methionine hydroxy analog, it was kept warm and stirred in the reactor for 30 min, and then transferred to the first crystallization kettle for cooling crystallization. The temperature at the end of crystallization was controlled at 30 °C. The materials in the crystallization kettle were put into a plate and frame filter press for pressure filtration. The pressure filtration mother liquor was transferred to the first methionine hydroxycalcium salt mother liquor storage tank for storage, and the temperature in the mother liquor storage tank I was kept at 30 - 35 °C. The volume of the mother liquor was 5.2 cubic meters, in which the content of methionine hydroxycalcium was 6.06 wt%, and the pH was 7.2. All of this mother liquor was applied to the water for slaking lime in the production process of the next batch of methionine hydroxycalcium salt (when the mother liquor was recycled, the methionine hydroxycalcium salt in the mother liquor needed to be deducted). The wet methionine hydroxy analog product from the plate and frame filter press entered a flash dryer for drying. The drying air temperature of the dryer was 125 °C, and the flash drying tail gas was directly sent to an incinerator for incineration treatment. 2.551 tons of the dried methionine hydroxycalcium salt product was stored in a storage tank. After sampling and analysis, the content of methionine hydroxycalcium salt was 97.5 wt% (where the content of methionine hydroxy analog was 84.5%, the calcium content was 13.0%, the lead content was 2 ppm, the arsenic content was 1 ppm, and the cadmium content was 0.5 ppm. The bulk density was 0.48 g / mL, spherical granular, and the particle size was 200 - 350 μm, with good fluidity). When the temperature of the methionine hydroxycalcium salt product in the storage tank dropped to 40 °C, it was transported to a packaging machine for sub-packaging. The results of the number of cycles are shown in Table 5

[0075] Table 5

[0076]

[0077]

[0078] It can be seen from the number of times of application in Table 5 above that as the number of times of application of the mother liquor increases, the quality of the methionine hydroxycalcium salt decreases (the content decreases, the heavy metals increase, and the particle size decreases, showing more powdery materials). When the number of times of application of the mother liquor exceeds 5 times, the heavy metals in the product are significantly unqualified.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention. The technologies, shapes, and structures not described in detail in the present invention are all well-known technologies.

Claims

1. A co-production preparation method of calcium hydroxy methionine and trace element chelated hydroxy methionine, characterized in that, It includes the following steps: Add hydroxy methionine to the calcium hydroxide emulsion and stir. Set the reaction temperature at 70 - 100 °C, the reaction pH at 6.5 - 8.0, and the reaction time at 30 - 120 min. After the reaction, cool down and filter to obtain the wet product of calcium hydroxy methionine and the crystallization mother liquor of calcium hydroxy methionine; Heat the crystallization mother liquor of calcium hydroxy methionine to 50 - 80 °C, then add trace element metal salts, and carry out a holding and stirring reaction at 60 - 80 °C for 60 - 150 min. During the reaction process, use calcium oxide or calcium hydroxide to control the pH at 6.5 - 7.

5. Cool down and filter to obtain the wet product of hydroxy methionine chelated trace elements, and dry it at 100 - 120 °C to obtain the hydroxy methionine chelated trace element product.

2. The co-production preparation method of calcium hydroxy methionine and trace element chelated hydroxy methionine according to claim 1, wherein, The calcium hydroxide emulsion is prepared by adding calcium oxide to water and stirring. The preheating temperature of the calcium hydroxide emulsion is 65 - 70 °C, and the feeding molar ratio of calcium oxide to water is 1:27.3 - 67.

7.

3. The co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine according to claim 2, characterized in that, The content of effective calcium in the calcium oxide is ≥70.0 wt%, arsenic ≤5 ppm, lead ≤20 ppm, cadmium ≤5 ppm, and the passing rate through a 200 - mesh sieve is ≥90%.

4. The co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine according to claim 3, characterized in that, The feeding molar ratio of calcium in the calcium hydroxide emulsion to hydroxy methionine is 1.90 - 2.10:0.98 - 1.

10.

5. The co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine according to claim 4, characterized in that, The hydroxy methionine is of commercial grade, with a percentage content of 88 wt%, containing 65 wt% of hydroxy methionine monomer, 23 wt% of dimer and polymer, 10 wt% - 12 wt% of water, and 0.5 wt% - 2.0 wt% of ammonium sulfate.

6. The co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine according to claim 1, characterized in that The pH value of the crystallization mother liquor of calcium hydroxy methionine is 6.5 - 8.0, and the percentage content of calcium hydroxy methionine is 5.0 wt% - 15.0 wt%.

7. The co-production preparation method of calcium hydroxymethionine and trace element chelated hydroxymethionine according to claim 1, characterized in that, The dosage of the trace element metal salt is 1.0 - 1.1 times or 2.0 - 2.1 times the molar amount of calcium hydroxy methionine in the crystallization mother liquor of calcium hydroxy methionine.

8. The co-production preparation method of calcium hydroxymethionine and trace element chelated by hydroxymethionine according to claim 7, characterized in that, The trace element metal salt is the chloride or acetate of divalent zinc ion, divalent copper ion, divalent manganese ion, ferrous ion, divalent nickel ion, divalent cobalt ion, and trivalent chromium ion.

9. The co-production preparation method of calcium hydroxymethionine and hydroxymethionine chelated trace elements according to claim 8, characterized in that The molar ratio of hydroxy methionine to metal ions in the hydroxy methionine chelated trace element product is 1:1 or 2:

1. The hydroxy methionine chelated trace element product is spherical with a particle size of 350 - 700 μm, and the main content of hydroxy methionine chelated trace elements is ≥97 wt%, arsenic ≤1 ppm, lead ≤5 ppm, and there is no cadmium.

10. The co-production preparation method of calcium hydroxy methioninate and trace element chelated hydroxy methionine according to claim 1, characterized in that, The wet product of calcium hydroxy methionine is dried at a temperature of 105 - 120 °C. The calcium hydroxy methionine obtained by drying is spherical with a particle size of 150 - 500 μm, the main content of calcium hydroxy methionine is ≥96 wt%, there is no arsenic, no lead, and no cadmium.

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