CN1037428C

CN1037428C - Method for prodn. of potassium sulfate by NaSO4 and KCl through metathesis

Info

Publication number: CN1037428C
Application number: CN95111303A
Authority: CN
Inventors: 杨大敏
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-03-30
Filing date: 1995-03-30
Publication date: 1998-02-18
Anticipated expiration: 2015-03-30
Also published as: CN1132180A

Abstract

The present invention relates to a technological method which takes sodium sulfate and sodium chloride as raw materials to carry out two-step double decomposition reaction in a water medium to produce potassium sulfate. The present invention is characterized in that aphthitalite (3K2SO4Na2SO) mother solution generated in the first-step double decomposition reaction is directly cooled, and mirabilite (Na2SO4.10H2O) separated out is used as raw materials to be cyclically used; the second-step double decomposition reaction is carried out at the temperature of 40 to 130 DEG C, potassium sulfate products in which not less than 50% of K2O and not more than 1.5% of Cl are contained can be obtained by stirring the reactant for 30 minutes. The total recovery rate (measured by K2O) is not less than 98%.

Description

Make the method for vitriolate of tartar by sodium sulfate and Repone K metathesis

The present invention relates to the manufacture method of a kind of sodium, potassium or general alkali-metal vitriol.

Vitriolate of tartar mainly decomposes method, promptly so-called Mannheim method and the manufacturing of improving one's methods thereof of Repone K at present as main chlorideless potassic fertilizer product with sulfuric acid.Owing to need handle deep-etching material (H down at high temperature (700 ℃ of reaction zones and burner hearth up to more than 1200 ℃) ₂SO ₄, HCl), therefore, the apparatus cost height, working condition is abominable.

Recently, people begin to watch attentively with the manufacturing of the metathesis process in water medium vitriolate of tartar.Wherein the most noticeable be the German Messo 1985-1992 of company succeed in developing, by sodium sulfate and Repone K under normal temperature (25 ℃), through glaserite [3K ₂SO ₄.Na ₂SO ₄Or NaK ₃(SO ₄) ₂] two step process of intermediate are [referring to documents Phosphorus ﹠amp; Potassium No.178, Mar-Apr 1992, P20-26].The reaction formula of two-step reaction is respectively:

The shortcoming of Messo method and other technology of metathesis production vitriolate of tartar in water by sodium sulfate and Repone K is, above-mentioned two step replacement(metathesis)reactions relate to solid phase with the material exchange alternate with solid-liquid, the nucleus of Chan Shenging and very easily produce absorption, the occlusion of impurity and carry secretly at normal temperatures at growth process, make product impure, thereby:

1, the reactor that needs particular design, promptly so-called pipe core shaft type crystallizer is controlled degree of supersaturation, thereby has improved apparatus cost.

2, the first step reaction needed for two steps finished again.This is because in order to reach K ₂The maximum yield of O, mother liquor are formed and should be formed near the common saturation point of sodium sulfate, sodium-chlor and glaserite as far as possible, but the glaserite intermediate K that generates this moment ₂O: Na ₂O (mol) has only (2.2-2.4): 1 (theoretical value is 3: 1) must further make K with the Repone K reaction ₂O: Na ₂O (mol) reaches more than 2.7: 1, just can be used for the reaction of second step, otherwise the product vitriolate of tartar is off quality, and this is one of committed step of Messo method.

Even 3 have adopted the reactor of particular design, the vitriolate of tartar crude product that the reaction of second step produces must just can be produced qualified potassium product through one washing procedure, i.e. second step reaction also needed for two steps finished, and the art breading water yield is increased, and energy consumption increases.

4, product vitriolate of tartar purity is low, has only 87.5-92.1% (to contain K ₂O47.3-49.8%), do not reach current in the world agricultural grade vitriolate of tartar quality standard (K as yet ₂O 〉=50%, Cl≤1.5%), after the washing purification process, also just can reach 96.0-98.0% and (contain K ₂O ₅1.9-53.0%).China's Qinghai potash fertilizer plant can only be produced K ₂O 〉=45% product.

The objective of the invention is: do not have " three wastes " discharging and total recovery (K in technological process ₂The O meter) 〉=98% under the prerequisite, provide a kind of product purity height (K ₂O 〉=50%, Cl≤1.5%), technical process is simple, and is with short production cycle, do not need specific equipment, and economic benefit and environmental benefit be the production method of the good vitriolate of tartar that is easy to apply all.

Accompanying drawing 1 is a technological process block-diagram of the present invention.

1 pair of implementation step of the present invention is described as follows by reference to the accompanying drawings:

(1) the first step replacement(metathesis)reaction

With round-robin and additional Repone K, round-robin and the sodium sulfate or the saltcake (Na that replenish ₂SO ₄.10H ₂O), round-robin and the water that replenishes and round-robin Repone K mother liquor and potassium sulfate mother liquid are pressed KCl: Na ₂SO ₄: H ₂O=1: (1.5-2.0): (2.5-3.0) weight ratio was 23-26 ℃ of following stirring reaction 6 hours.Filter (centrifugal) and go out glaserite, the gained liquid phase is that the glaserite mother liquor is cooled to 0 ℃, separates out saltcake Na ₂SO ₄.10H ₂O, its filtration (centrifugal) is separated, gained solid saltcake returns the utilization of the first step reaction cycle, the gained liquid phase is that the saltcake mother liquor must be paid product sodium-chlor by solid through evaporation, thickening filtration (centrifugal), the water of evaporation reclaims through condensation and makes the first step and second step reaction batching water, and elimination sodium-chlor is mother liquid obtained, is cooled to room temperature, filter (centrifugal) and obtain the raw material recycle that solid Repone K is done the first step or second step, the mother liquor of elimination Repone K returns the utilization of the first step reaction cycle.

(2) second step replacement(metathesis)reactions

With the solid glaserite that the first step Reaction Separation goes out,, press KCl: glaserite: H with fresh and circulation Repone K and fresh and recirculated water ₂O (weight ratio) 1: (1.4-1.6): (2.0-2.4) proportioning is filtered (centrifugal) and is obtained K 40-130 ℃ of following stirring reaction 30 minutes ₂O 〉=50%, the potassium product of Cl≤1.5%, its mother liquor return the utilization of the first step reaction cycle.

The first step replacement(metathesis)reaction also can be carried out under comparatively high temps (40-100 ℃), thereby will shorten to half an hour approximately the reaction times.But reaction mass must be cooled to 25 ℃ of separation, the glaserite yield is improved, the more important thing is, sodium chloride concentration maximum in the glaserite mother liquor that only under 25 ℃, obtains (about 23.4%), thereby evaporated water minimum when making the back reclaim NaCl.Therefore it is not obvious that the first step is reacted the benefit of at high temperature carrying out.

From thermodynamics (phasor) angle, the second step replacement(metathesis)reaction is at high temperature carried out K ₂The O yield can reduce, and therefore this reaction is for a long time all carried out at 25 ℃.But careful calphad shows, vitriolate of tartar itself and Repone K and glaserite altogether 25 ℃ of solubleness in the saturated solution be 2.1%, 50 ℃ to be 1.9%, 60 ℃ be 2.0%, 100 ℃ of ability 2.7%, therefore since the rising of temperature to K ₂The reduction of O yield influence is very little, and this is because KCl concentration increases the common-ion effcet that is produced have been compensated temperature and raise to the influence of yield, solubility change this two kinds of results that factor disappears and rises just under the differing temps; On the other hand, owing to vitriolate of tartar crude product of the present invention does not need further to wash purifying, thereby actual recovery also can improve.

The present invention compares with the Messo method owing to the crystallization purity height that produces under comparatively high temps, and the crude product vitriolate of tartar need just can not reach K through the washing purification step ₂O 〉=50%, the quality standard of Cl≤1.5% (actual≤1.0%) if further wash purifying, can make product K ₂SO ₄Purity reaches more than 99%, thereby satisfies technical grade, pharmaceutical grade or other product requirement to purity requirement.

The present invention is keeping the Messo method not have discharging and total K ₂On the basis of O rate of recovery height (〉=98%), reduced by four procedures, eliminated the requirement of the reactor of particular design.Simultaneously, since same when pyroreaction can shorten reaction greatly, labour productivity and plant factor improved; Owing to need not wash the purifying water, the art breading water yield is reduced again.Therefore the present invention descends apparatus cost and production cost significantly; Also, two-step reaction lays the foundation continuously for being incorporated in the reactor.

Relatively seeing the following form of the present invention and Messo method:

	Reactor	The second step temperature of reaction	Processing step	Thick product purity	Purified product purity
	Reactor	The second step temperature of reaction	Processing step	Thick product purity	Purified product purity	Messo technology	Particular design	～25℃	14	87.5- 92.1％	96.0- 98.0％
Technology of the present invention	Universal	40-130℃	10	92.5- 94.5％	99.0％	Messo technology	Particular design	～25℃	14	87.5- 92.1％	96.0- 98.0％

If being reflected under the comparatively high temps (for example 〉=40 ℃), carry out in the first step and second step, some other factor then, as the addition sequence of reactant with add implantation site, alr mode and speed, type of heating and heat-up rate etc., the influence of technology and product purity is seemed inessential.Reactant (KCl, Na ₂SO ₄, glaserite and water) can add simultaneously or any material adds earlier and adds other material gained result again and do not have significant difference.Stirring velocity can be selected in 80-300 rev/min.

Temperature of reaction of the present invention generally just can obtain satisfied result down at 50-90 ℃.At higher temperature, reaction gained result and 50-90 ℃ of reaction gained result do not have significant difference under the boiling point (110-130 ℃) of solution.Reaction of the present invention is all carried out under normal pressure, is being nonsensical above reaction under the boiling point, only can increase energy consumption and make process complicated.

Below three embodiment the invention will be further described.

Embodiment 1:

With 142 gram Na ₂SO ₄(99%) and 90 gram KCl (Jordan produces, K ₂O 〉=60%) and 240 gram water stirred 6 hours down at room temperature 23-26 ℃, suction filtration, oven dry, glaserite intermediate 120 grams.This intermediate is divided into two parts, and portion is done following experiment, and portion compares experiment.

Get 60 gram glaserite intermediates, (Jordan produces, K to add 40.6 gram KCl ₂O 〉=60%), water 94 gram stirs down and is heated to 45-55 ℃, under this temperature, reacted 30 minutes, suction filtration, dry product K ₂SO ₄54.8 gram, it is as follows to press ZBG 21006-89 national standard analytical results:

K ₂O 50% Cl is water 0.6% O.6%

Control experiment:

40 gram embodiment 1 gained glaserite intermediates add 27.1 gram KCl, 64 gram water, be interrupted stir under, room temperature reaction one day, suction filtration, dry product vitriolate of tartar 40.6 grams, analytical results:

K ₂O 46.6% Cl 4.12% water 0.6%

Embodiment 2:

With thick potassium product 30 grams of gained in the reference examples, (Jordan produces, K to add water 24 gram KCl ₂O 〉=60%) 6.5 grams, 70-80 ℃ of stirring reaction 30 minutes, suction filtration, dry K ₂SO ₄Product 26.7 grams, analytical results:

K ₂O 53.5% Cl O.3% water 0.2% (is equivalent to 99%K ₂SO ₄)

Embodiment 3:

Take by weighing 180 gram Na ₂SO ₄(99%), (Jordan produces 100 gram KCl, K ₂O 〉=60%), 280 gram water stirred 6 hours down in room temperature (24-26 ℃), suction filtration, dry glaserite intermediate 128 grams, get 100 gram glaserites wherein, (Jordan produces, K to add 64.5 gram KCl ₂O 〉=60%), 140 gram water, (about 125 ℃ of temperature of reaction) stirring reaction is 30 minutes under refluxing, and cold slightly back suction filtration is dried to such an extent that potassium product 89 restrains analytical results:

K ₂O 51.1% Cl 0.1% water 0.2%

Claims

1, a kind of method of making vitriolate of tartar by sodium sulfate and Repone K metathesis is characterized in that the first step reaction is by Repone K: sodium sulfate: water is 1: (1.5-2.0): weight ratio (2.5-3.0), 23-26 ℃ of reaction 6 hours, leach glaserite, mother liquid obtainedly be cooled to 0 ℃, separate out saltcake (Na ₂SO ₄.10H ₂O) return the utilization of the first step reaction cycle, the mother liquor of elimination saltcake obtains paying a product sodium-chlor through evaporating, concentrate, filtering, the water condensation of evaporation reclaims makes the first step and second step reaction batching water, the mother liquor of elimination sodium-chlor, be cooled to the room temperature filtration and obtain the raw material recycle that Repone K is done the first step and second reaction, the mother liquor of elimination Repone K returns the utilization of the first step reaction cycle; The second step reaction is by Repone K: glaserite: water is 1: (1.4-1.6): weight ratio (2.0-2.4), 40-130 ℃ of following stirring reaction 30 minutes, filtration obtained K ₂O 〉=50%, the potassium product of Cl≤1.5%, its mother liquor return the utilization of the first step reaction cycle.