Sulfuric acid calcium phosphate reaction with

It is generally agreed that the reaction proceeds in two stages (1) the sulfuric acid reacts with part of the rock, forming phosphoric acid and calcium sulfate and (2) the phosphoric acid formed in the first step reacts with more phosphate rock, forming monocalcium phosphate. The two reactions take place concurrently, but the first stage is completed rapidly while the second stage continues for several days or weeks. 

C04-0146. The largest single use of sulfuric acid is for the production of phosphate fertilizers. The acid reacts with calcium phosphate in a 2 1 mole ratio to give calcium sulfate and calcium dihydrogen phosphate. The mixture is crushed and spread on fields, where the salts dissolve in rain water. (Calcium phosphate, commonly found in phosphate rock, is too insoluble to be a direct source of phosphate for plants.) (a) Write a balanced equation for the reaction of sulfuric acid with calcium phosphate, (b) How many kilograms each of sulliiric acid and calcium phosphate are required to produce 50.0 kg of the calcium sulfate-dihydrogen phosphate mixture (c) How many moles of phosphate ion will this mixture provide ... 

Two major methods are utilized for the production of phosphoric acid from phosphate rock. The wet process involves the reaction of phosphate rock with sulfuric acid to produce phosphoric acid and insoluble calcium sulfates. Many of the impurities present in the phosphate rock are. also solubilized and retained in the acid so produced. While they are of no serious disadvantage when the acid is to be used for fertilizer manufacture, their presence makes the product unsuitable for the preparation of phosphatic chemicals. 

The majority of the phosphoric acid is made by the wet process, which involves reaction of calcium phosphate or the mixed calcium fluoride-calcium phosphate ores with sulfuric acid. 

Because of its use in the manufacture of fertilizers, calcium phosphate is a compound of enormous importance. After being mined, it is converted into Ca(H2P04)2 by treating it with sulfuric acid. This converts the insoluble Ca3(P04)2 into a soluble, more efficient form (see Section 13.9). The reaction can be written as... 

When pulverized calcium phosphate is treated with sulfuric acid (the least expensive strong acid), the reaction is... 

Phosphoric acid is prepared by the reaction of calcium phosphate with sulfuric acid ... 

The first term on the right-hand side, i.e., calcium hydrophosphate is not in pure form in actual process. It contains impurities from the ore and is sold commercially as TSP fertilizer. It is also possible to produce a similar phosphate product by reacting phosphate ore with sulfuric acid. The reaction proceeds according to reaction 3.3 [3]... 

What masses of calcium sulfate and phosphoric acid can be produced from the reaction of 1.0 kg of calcium phosphate with 1.0 kg of concentrated sulfuric acid (98% H2S04 by mass) ... 

Wet Process. The reactions in the digestion of apatite with sulfuric acid are complex. The calcium phosphate portion of apatite reacts with sulfuric acid as follows ... 

Eq. 10.34) is more rapid with hydrochloric acid than with sulfuric acid, and yields soluble products from both the calcium and phosphate. Thus, there is neither a need to heat the mixture to speed up the reaction, nor are there any crystal form problems requiring temperature stabilization. 

There are many oxoacids containing phosphorus. Some examples are phosphorous acid, H3PO3 phosphoric acid, H3PO4 hypophosphorous acid, H3PO2 and triphosphoric acid, H5P3O10 (Figure 21.11). Phosphoric acid, also called orthophosphoric acid, is a weak triprotic acid (see p. 619). It is prepared industrially by the reaction of calcium phosphate with sulfuric acid ... 

LAPIS INFERNALIS (7761-88-8) A powerful oxidizer. Forms friction- and shock-sensitive compounds with many materials, including acetylene, anhydrous ammonia (produces compounds that are explosive when dry), 1,3-butadiyne, buten-3-yne, calcium carbide, dicopper acetylide. Contact with hydrogen peroxide causes violent decomposition to oxygen gas. Violent reaction with chlorine trifluoride, metal powders, nitrous acid, phosphonium iodide, red or yellow phosphorus, sulfur. Incompatible with acetylides, acrylonitrile, alcohols, alkalis, ammonium hydroxide, arsenic, arsenites, bromides, carbonates, carbon materials, chlorides, chlorosulfonic acid, cocaine chloride, hypophosphites, iodides, iodoform, magnesium, methyl acetylene, phosphates, phosphine, salts of antimony or iron, sodium salicylate, tannic acid, tartrates, thiocyanates. Attacks chemically active metals and some plastics, rubber, and coatings. 

Sodium fluoride occurs naturally as the mineral villiau-mite, although the compound is not produced commercially from that source. Some sodium fluoride is obtained as a byproduct of the manufacture of phosphate fertilizers. In that process, apatite (a form of calcium phosphate that also contains fluorides and/or chlorides) is crushed and treated with sulfuric acid (H2S04). The products of that reaction include phosphoric acid (H3P04), calcium sulfate (CaS04),... 

The purpose of the reaction step is not only to extract the pho hate from the rock but also to ensure slow growth of gypsum crystals to a relatively large size. To attain this goal, reaction systems are designed to prevent direct contact between the two reactants, phosphate rock, and sulfuric acid. A hi concentration of free sulfuric add would result in coating the phosphate rock with calcium sulfate reaction product, thus Hocking further reaction. 

The solution obtained by reaction of nitric acid with phosphate rock can be treated by the addition of a soluble sulfate to precipitate part or nearly all of the calcium as calcium sulfate (gypsum or hemihydrate). In commercial processes, ammonium sulfate, potassium sulfate, and sulfuric acid have been used. Langbeinite (K2S04 2MgS04) has been used experimentally. The calcium sulfate may be separated by filtration or allowed to remain in the product. In most plants, the calcium sulfate is removed to produce a higher grade product. Chemical reactions are ... 

Superphosphate is produced by reacting calcium phosphate with sulfuric acid according to the reaction... 

Solid calcium phosphate and aqueous sulfuric acid solution react to give calcium sulfate, which comes out of the solution as a solid. The other product is phosphoric acid, which remains in solution. Write a balanced equation for the reaction using complete formulas for the compounds with phase labels. 

This method produces a very pure phosphoric acid. A less pure product forms from the reaction of calcium phosphate (a mineral source of phosphate) with concentrated sulfuric acid. 

---