CN85102898A

CN85102898A - The coming of new method of potassium primary phosphate

Info

Publication number: CN85102898A
Application number: CN 85102898
Authority: CN
Inventors: 袁建高; 罗琨琴
Original assignee: INSTITUTE OF CHEMICAL INDUSTRY GUIZHOU PROV
Current assignee: INSTITUTE OF CHEMICAL INDUSTRY GUIZHOU PROV
Priority date: 1985-04-01
Filing date: 1985-04-01
Publication date: 1987-01-17

Abstract

Make the method for potassium primary phosphate.Original method is owing to these products of cause influence such as raw materials cost height or complex process develops rapidly.The present invention phosphorus ore (P ₂O ₅More than 28%), sulfuric acid and vitriolate of tartar be raw material, a step makes Ca (H earlier ₂PO ₄) ₂Solution is used K ₂SO ₄Carry out replacement(metathesis)reaction with it and use native alkali (K again ₂CO ₃, contain K ₂O60%) transfer pH3-5, filtered liquid can obtain KH through concentrated, crystallization, drying ₂PO ₄Content 80～85%.This law yield height, the acid consumption only is 2/3rds of a direct method.General Pu Gaichang and have vitriolic factory field to be suitable for, because at the bottom of the cost, the suitable composite fertilizer of doing of product.

Description

The coming of new method of potassium primary phosphate

The invention belongs to the method for making potassium primary phosphate.

Up to now, the acid-base neutralisation manufactured is adopted in the production of potassium primary phosphate more.Because the cost height has limited its development greatly.Result through domestic and international research work for many years, many new manufacturing technologies have appearred, from＜make discussion＞(the Sichuan chemical industry of potassium primary phosphate operational path with Rock Phosphate (72Min BPL) and sylvite, 1984 № 1P38～41) can see, operational path is to make phosphoric acid by wet process with cheap phosphorus ore to replace thermal phosphoric acid preferably now, uses cheap sylvite (as KCL or K simultaneously ₂SO ₄) expensive potassium hydroxide or the salt of wormwood of replacement, wherein advanced " substep decomposition method " (1) adopts the sulfuric acid decomposing phosphate rock to make phosphoric acid by wet process, (2) make monocalcium phosphate with lime carbonate or lime neutralization then, (3) add vitriolate of tartar again and carry out replacement(metathesis)reaction and obtain potassium dihydrogen phosphate, (4) with in the potassium hydroxide and residue phosphoric acid generate potassium primary phosphate.Solution concentration, cooling, crystallization, separation with gained at last promptly obtains potassium dihydrogen phosphate product.This method respectively to go on foot reaction formula as follows:

Though this method can obtain the KH of higher degree ₂PO ₄, but because＜1 adopting two water law system phosphoric acid, phosphorus ore and acid consumption are all higher, still will adopt the KOH neutralization at last.

In view of known technology can not satisfy industrial needs, the inventor with seek cheap raw material, technology is easy, yield is high and product cost is low operational path is a purpose, through research, has obtained satisfied effect.

It is raw material that method of the present invention adopts phosphorus ore, sulfuric acid and vitriolate of tartar.Should in the reactor (having agitator) of three polyphones, carry out after synthetic.Sulfuric acid (more than 70%) and ground phosphate rock (P ₂O ₅More than 28%) add in first reactor by stoichiometry, after the hybrid reaction 0.5～1 hour, generate heavy-gravity monocalcium phosphate slip, put it into second reactor, add vitriolate of tartar, stirred 1 hour, generate just that solid load is 25～40% in the slip, allow slip enter the 3rd reactor, with native alkali (K ₂CO ₃, K ₂O60%) PH is transferred to 3～5, reaction product is separated after filtration, and filtrate promptly gets KH through concentrated, crystallization ₂PO ₄Product.

P in the reaction mass of the present invention ₂O ₅: K ₂The O(mole ratio) be 1: 1-1.2, phosphorus ore impurity there is not particular requirement, in reaction, the principal reaction formula that temperature is controlled at 80～110 ℃ of the present invention is as follows:

Products obtained therefrom KH ₂PO ₄Content 80～85%, (P ₂O ₅Be 40～42%, K ₂O is 28～30%).

Because raw material is inexpensive, do not want solvent again, make KH ₂PO ₄Relatively the traditional method cost descends significantly, compares sour consumption with the direct method that will make phosphoric acid by wet process earlier and will lack 1/3rd.Especially phosphorus ore impurity there is not particular requirement, P ₂O ₅Getting final product more than 25%, native alkali price is industrial goods K ₂CO ₃2/5ths.So general medium and small Pu Gaichang and vitriol works are produced composite fertilizer by this method easily.

Embodiment 1, with containing 36%P ₂O ₅Phosphorus ore 400 grams, 115 milliliters in the sulfuric acid of adding concentration 87% dilutes with 70 ml waters, stir half an hour down at 80 ℃, generate phosphoric acid-calcium slip, flow into second reactor, add 198 gram vitriolate of tartar (being made into saturated solution), stirred 1 hour down at 94 ℃, synthetic potassium primary phosphate slip enters the 3rd reactor, with the native alkali neutralization of 116 grams, make acidity be transferred to PH=4.5, reaction is finished.Slip is in filtering separation, and concentrating filter liquor, crystallization get product K H ₂PO ₄, content 89.4%.

Embodiment 2, the sulfuric acid 260 that adds proportion 1.8 with phosphorus ore 500 grams restrains, and adds the dilution of 110 ml waters, stirs half an hour down at 85 ℃, flow into second reactor, add 248 gram vitriolate of tartar (or becoming saturated solution), stirred 1 hour down at 94 ℃, slip flows into the 3rd reactor, add the native alkali of 150 grams, PH is transferred to 4.5 reactions finishes, slip separates, and concentrating filter liquor, crystallization get product K H ₂PO ₄Content 91.4%.

Embodiment 3, phosphorus ore 500 grams add sulfuric acid 260 grams, add 110 milliliters in water, mixed 1 hour at 90 ℃, slip flows into second reactor, add sylvite 200 grams (saturated solution) and carry out building-up reactions, generate slip and enter the 3rd reactor, add native alkali 150 grams, transfer PH=4.2, separate slip, concentrating filter liquor, crystallization get product K H ₂PO ₄, content 92.3%.

Claims

1, makes monocalcium phosphate is made potassium primary phosphate again with vitriolate of tartar method with phosphorus ore and sulfuric acid, it is characterized in that building-up reactions carries out in the reactor of three polyphones, sulfuric acid and ground phosphate rock added in first reactor by stoichiometry react, the monocalcium phosphate slip that reaction generates is put into the second anti-reactor ， And adding vitriolate of tartar and is carried out replacement(metathesis)reaction.Reaction is put into the 3rd reactor to slip after finishing, and adds the alkali (K that buries simultaneously ₂CO ₃, contain K ₂O60%) transfer PH3～5, slip is gained filtrate after filtration, promptly obtains potassium primary phosphate through concentrated, crystallization.

2, method according to claim 1 is characterized in that the raw material phosphorus ore (is contained P ₂O ₅More than 28%) impurity can not do requirement, sulfuric acid is more than 70%, P in the reaction ₂O ₅: K ₂O=1: 1～1.2 is reinforced.

3, method according to claim 1 is characterized in that reaction process will continuous violent stirring.Temperature of reaction should be controlled at 80～110 ℃.

4, method according to claim 1 is characterized in that in second reactor reaction proceeds to solid phase and accounted at 25～40% o'clock, promptly slip can be put into the 3rd reactor.