Background and Overview
Also known as monocalcium phosphate, the chemical formula is Ca(H2PO4)2•H2O, and the formula weight is 252.07. White triclinic crystal. The density is 2.22g/cm3, it loses crystal water at 109℃ and decomposes at 203℃. Easy to deliquesce, soluble in water, insoluble in ethanol. It is used as analytical reagents, plastic stabilizers, and as phosphate fertilizer in agriculture. It is prepared by dissolving calcium phosphate in phosphoric acid. Usage: Food additive, a moisture retaining agent for food permitted by my country’s GB2760-1996; also used as leavening agent, dough modifier, nutritional supplement, chelating agent and yeast food; also used as plastic stabilizer.
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Applied Research
Li Zhanfu et al. studied the effects of the appropriate addition amount of calcium monophosphate (MCP) in a high-fat (7%) practical diet for grass carp on the growth performance, lipid metabolism and antioxidant capacity of grass carp. They used calcium monophosphate [Ca ( H2PO4)] as the phosphorus source, prepare five kinds of isonitrogenous and isoenergetic practical diets containing MCP of 0 (control group), 1.0%, 2.0%, 3.0% and 4.0%. The initial average weight of feeding is (105.23±0.55 ) g of experimental grass carp, each diet was set up with 3 replicates, 15 fish in each replicate, and an 8-week breeding trial was conducted. The results show that adding appropriate MCP to high-fat diet can significantly increase grass carp weight gain rate (WGR) and whole fish phosphorus content, and reduce feed coefficient (FCR) and visceral body ratio (VSI). Using WGR, FCR and whole fish phosphorus as observation indicators, the broken line model analysis showed that the appropriate dietary MCP addition amounts are 3.26%, 2.96% and 2.63% respectively; the crude fat content of whole fish, viscera, muscle and liver changes with the MCP in the diet. The increase showed a trend of first decreasing and then increasing, while the crude protein content of whole fish and muscle showed an opposite trend; in the MCP3.0% group, the intestinal amylase, lipase and trypsin activities of grass carp, serum alkaline phosphatase (AKP) The highest activity, serum triglyceride, liver malondialdehyde content, and the lowest acetyl-coenzyme A carboxylase (ACC) activity; serum total cholesterol content in the supplemented group were significantly lower than those in the control group (P<0.05), liver carnitine acyl transfer Enzyme (CPT-I) activity gradually increased with the increase in dietary MCP addition. Studies have shown that the appropriate addition level of MCP in grass carp's high-fat (7%) diet is 2.96%-3.26% (total feed phosphorus 1.43%-1.50%). This addition level can promote the digestion and utilization of nutrients in the diet by grass carp. Reduce fish and liver fat accumulation, increase fish protein, improve antioxidant function, and promote growth.
Wang Shuang et al. used juvenile Xiangyun crucian carp with an initial weight of (40.00±0.34) g as the research object, and randomly divided them into 6 groups (each group had 3 replicates, each replicate had 20 fish), respectively. Six kinds of practical isonitrogenous and isoenergetic feeds with dicalcium phosphate (MCP) addition amounts of 1.0%, 1.5%, 2.0%, 2.5%, 3.0% and 3.5% were fed and an 8-week breeding trial was conducted to study The appropriate amount of MCP added to the feed of Xiangyun crucian carp. The results showed that with the increase in the amount of MCP added to the feed, the final average weight and weight gain rate (WGR) of Xiangyun crucian carp showed a trend of first increasing and then decreasing, and the feed coefficient (FCR) showed a trend of decreasing and then increasing. The average weight and WGR reached the highest value when the MCP addition amount was 2.5%, and the FCR reached the lowest value when the MC Indonesian stearic acid P addition amount was 3.0%. As the amount of MCP added to the feed increases, the crude fat content of the whole fish, muscles and liver of Xiangyun crucian carp first decreases and then increases, reaching the lowest value when the amount of MCP is added to 2.5%, while the crude protein content of the whole fish and the content of the whole fish and spine bone phosphorus content reached the highest value at this addition amount. There was no significant difference in the water content of whole fish among the groups (P>0.05). When the MCP addition amount is 2.5%, the activity of intestinal amylase petroleum resin, lipase, trypsin, and serum superoxide dismutase and alkaline phosphatase activities reach the highest value, and the serum triglyceride content and liver propylene glycol Aldehyde content reaches a minimum. There was no significant difference in serum cholesterol content between groups (P>0.05). The serum phosphorus content first increased and then stabilized with the increase in the amount of MCP in the feed, and there was no significant difference in serum calcium content between the groups (P>0.05). Taking WGR, FCR, whole fish and spine bone phosphorus content as observation indicators, and through quadratic curve model and broken line model analysis, it was concluded that the appropriate addition amount of MCP in Xiangyun crucian carp feed is 2.55% to 2.71%.
Production method
There are three main production methods for pre-feed grade calcium dihydrogen phosphate (Ca(H2PO4)2•H2O):
One method is to dilute hot phosphoric acid with water to a P2O5 content of 54wt%, and neutralize it with calcium compounds (calcium carbonate, calcium oxide, calcium hydroxide, defluorinated tricalcium phosphate) dry powder or liquid phase to generate phosphoric acid Calcium dihydrogen slurry is then spray-dried or air-flash-dried to produce a semi-finished product. The semi-finished product is matured and dried in a kiln to obtain the finished product.
The second method is that some companies use wet concentration to purify phosphoric acid, add 50wt% thermal phosphoric acid, and prepare phosphoric acid with a low impurity content of 54wt% P2O5, and then mix it with calcium compounds (calcium oxide, hydroxide Calcium, defluorinated tricalcium phosphate) dry powder or liquid phase neutralization reaction to generate calcium dihydrogen phosphate slurry, which is then spray-dried or flash-dried to produce a semi-finished product. The semi-finished product is matured, rotated or flash-dried to obtain the finished product.
The third method is to produce in two steps. In the first step, the phosphate rock is extracted with inorganic acid (sulfuric acid, hydrochloric acid) to extract dilute phosphoric acid, and the dilute phosphoric acid is added to the liquid phase with calcium-containing compounds (calcium oxide, calcium hydroxide). And reaction defluorination, the defluoridated acid slurry adopts mechanical filtration to separate fluorine-containing compounds (CaF2, CaSiF6) while generating Ca(H2PO4)2·H2O, Fe3(PO4)2, AlPO4, etc., and the acid residue is filtered to produce fertilizer grade calcium hydrogen phosphate. , to obtain defluorinated phosphoric acid, defluorinated dilute phosphoric acid and liquid phase calcium-containing compounds (calcium carbonate, calcium oxide, calcium hydroxide, defluorinated tricalcium phosphate) generate hydrogen calcium phosphate CaHPO4·2H2O containing half moistureThe finished product is dried to obtain the finished calcium hydrogen phosphate product. In the second step, add 54wt% P2O5 content, 30wt% thermal phosphoric acid and 20wt% wet defluorinated concentrated phosphoric acid to the wet semi-finished or finished product of calcium hydrogen phosphate CaHPO4·2H2O, causing a liquid-solid reaction to generate dicalcium phosphate slurry or The moisture-containing semi-finished product of calcium dihydrogen phosphate is spray-dried or flash-dried to obtain the finished product.
Main reference materials
[1] Practical Chemistry Dictionary for Middle School Teachers
[2] Practical Fine Chemical Dictionary
[3] Li Zhanfu, Luo Jinqiang, Yang Huishi, Luo Hao, Li Yu, Chen Yongjun, Luo Li. Research on the appropriate addition amount of calcium dihydrogen phosphate in high-fat diet of grass carp [J]. Acta Hydrobiologica Sinica, 2019, 43 (02):243-251.
[4] Wang Shuang, Luo Li, Shi Yaqing, Tang Yi, Li Zhanfu, Li Weilong, Luo Hao. Appropriate addition amount of calcium dihydrogen phosphate in the feed of Xiangyun crucian carp [J]. Journal of Animal Nutrition, 2018, 30(10 ):3985-3992.
[5] [China invention, China invention authorization] CN201210206325.6 Method for producing feed grade calcium dihydrogen phosphate from wet phosphoric acid
