CN1785810A

CN1785810A - One step method for production of potassium sulphate using extraction crystallization reaction

Info

Publication number: CN1785810A
Application number: CN 200410081429
Authority: CN
Inventors: 沙启志; 段继敏; 应幼平
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-12-06
Filing date: 2004-12-06
Publication date: 2006-06-14

Abstract

The present invention relates to a method for producing potassium sulfate by adopting extraction crystallization one-step process. Said method includes the following steps: making calcium salt and ammonium hydrogen carbonate undergo the process of metathetic reaction to obtain ammonium hydroxide, then making it be reacted with potassium hydrogen sulfate prepared by using reaction of sulfuric acid and potassium chloride to obtain potassium ammonium sulfate salt solution, then adding potassium chloride to make metathetic reaction and extraction to obtain potassium sulfate, in the reaction process its by-products are active calcium carbonate, (potassium) ammonium chloride and barium chloride, etc.

Description

One-step method for producing potassium sulfate by extraction crystallization reaction

The technical field is as follows: the invention relates to a production method of an inorganic fertilizer.

Background art: potassium chloride (KCl) is commonly applied in the production of commercial crops such as tea and flue-cured tobacco, but the chlorine element of the potassium chloride is absorbed in the commercial crops to be very harmful to human bodies, and at present, potassium sulfate is used as a substitute for the potassium chloride. The production of potassium sulfate is commonly carried out by a Mannheim method, namely a high-temperature calcination method, and sulfuric acid and potassium chloride are calcined and decomposed into hydrogen chloride and potassium sulfate at the high temperature of more than 650 ℃, so that the corrosion is high, the requirement on the specificity of equipment is strong, the generation speed of the hydrogen chloride is difficult to control, and the environmental pollution is very easy to cause. The double decomposition of ammonium sulfate and potassium chloride to produce potassium sulfate is also one of the common methods, and has the disadvantages of insufficient resource of ammonium sulfate and high production cost. The patent technology for producing potassium sulfate by using desulfurized gypsum has the defects of difficult control of production, high production cost, high product selling price and difficult agricultural acceptance.

The invention content is as follows: the invention aims to overcome the defects in the prior art and provide a production technology for producing the potassium sulfide by one-step method through extraction and crystallization reaction, low-temperature production is realized, the production process is simplified, the pollution to the environment is reduced, local resources are fully utilized, and low production cost and equipment investment are eliminated. The purpose of the invention is realized as follows: the production process of potassium sulfate by one-step method of extraction crystallization reaction comprises the following steps: (1) adding ammonium bicarbonate NH into the raw material which is high-quality calcium salt for carbon elimination₄HCO₃Performing double decomposition reaction, adding 1-3% of alkaline compound auxiliary agent, heating to 89 + -3 deg.C to obtain NH₄OH, remainder precipitated activated calcium carbonate CaCO₃And centrifugally separating, drying and crushing to prepare the industrial raw material. (2) Mixing potassium chloride KCl and sulfuric acid H₂SO₄Reacting in a reaction kettle for 30-60min at 80-112 deg.C to obtain potassium bisulfate and hydrogen chloride And absorbing HCl ↓. (3) Mixing potassium hydrogen sulfate with NH₄OH reaction to prepare potassium sulfate ammonium salt solution Then adding potassium chloride for double decomposition reaction for 40-120min at 80-112 deg.C, and extracting to obtain potassium sulfate and ammonium chloride And the by-product of ammonium chloride NH₄Cl concentration, crystallization and centrifugal separation. (4) To be absorbedReacting tail gas HCl with barium carbonate ore for 120-240min, press-filtering, processing the slag into cement early strength agent, crystallizing the filtrateTo obtain barium chloride 。(5)NH₄The preparation of (1): adjusting calcium hydroxide to 22-25 Baume slurry, adjusting ammonium bicarbonate to 30% solution, slowly heating to 25-89 deg.C for reaction, strongly stirring for gas-liquid separation, absorbing the generated ammonia gas with water for use 。

The method organically combines the Mannheim method for preparing the potassium sulfate with the ammonium sulfate and potassium chloride double decomposition method, and double decomposition extraction reaction is completed in a reaction kettle, thereby avoiding loss caused by turnover in production and reducing labor intensity; the low-temperature reaction saves energy, improves the yield, has simple process and saves equipment investment; local materials are used, and local resource advantages are fully exerted; all reaction products are used to prepare by-products, no waste is generated, and no adverse effect is caused to the production environment. The main product potassium sulfate is used as potassium resource fertilizer for crops which are not easy to be chloridized, especially for economic crops, the ammonium chloride (potassium) is used as grain and oil compound fertilizer, the active calcium carbonate is used in the production of plastics, rubber, paper making, paint, etc., the barium chloride is used for the purification treatment of salt water, and is widely used for the environmental protection treatment in the industries of alkali making, paper making, tanning, pharmacy, dye, etc.

Description of the drawings: FIG. 1 is a flow chart of the production process.

The specific implementation mode is as follows: removing lime 100kg, mashing, adding ammonium bicarbonate NH₄HCO₃80kg of the mixture is subjected to double decomposition reaction, added with a reaction auxiliary agent NaOH2kg, evenly mixed, put into a reaction kettle and slowly heated to 25-89 ℃, and NH is absorbed by water₃To form NH₄And (5) OH. Obtaining active calcium carbonate by precipitation of excess materials Centrifugal separation, baking and crushing to obtain industrial raw material for plastics, rubber, paper-making and coatingIndustrial production of materials and the like. (2) Taking potassium chloride KCl25kg and sulfuric acid H₂SO₄30kg of the mixture is put into a reaction kettle to react for 30-60min at the temperature of 80-112 ℃ to prepare potassium bisulfate and hydrogen chloride And absorbing HCl ↓. (3) Potassium hydrogen sulfate and NH₄OH reaction, NH produced in the step (1)₄OH is added into a reaction kettle to prepare potassium sulfate ammonium salt solution Adding potassium chloride 23kg for double decomposition reaction at 80-112 deg.c for 40-120min to obtain potassium sulfate and ammonium chloride And the by-product of ammonium chloride NH₄Cl concentration, crystallization and centrifugal separation to prepare the raw material which is used as the grain and oil compound fertilizer. (4) Reacting tail gas HCl absorbed by water with barium carbonate ore of city to prepare barium chloride, firstly, the barium carbonate ore powder is firstly mixed with the tail gas HClCrushing, reaction in reactor for 120-240min, press filtering to obtain early cement strength agent, crystallizing the filtrate to obtain barium chloride . The prepared barium chloride is used for purifying brine and is widely used for environment-friendly treatment in the industries of alkali making, papermaking, tanning, pharmacy, dye and the like. (5) NH (NH)₄The preparation of (1): taking 150kg of calcium hydroxide to prepare slurry with the concentration of 22-25 Baume, preparing 100kg of ammonium bicarbonate to prepare solution with the concentration of 30%, mixing and stirring the two solutions uniformly, slowly heating to react at 25-89 ℃, carrying out gas-liquid separation under strong stirring, and absorbing the generated ammonia gas with water for later use. Reaction formula is 。

Claims

The one-step method for producing potassium sulfate by extraction crystallization reaction is characterized in that the production process comprises the following steps:

(1) adding ammonium bicarbonate NH into the raw material which is high-quality calcium salt for carbon elimination₄HCO₃Performing double decomposition reaction, adding 1-3% of alkaline compound auxiliary agent, heating to 89 + -3 deg.C to obtain NH₄OH, remainder precipitated activated calcium carbonate CaCO₃Centrifugally separating, drying and crushing to prepare industrial raw materials;
(2) mixing potassium chloride KCl and sulfuric acid H₂SO₄Reacting in a reaction kettle for 30-60min at 80-112 deg.C to obtain potassium bisulfate and hydrogen chloride Absorbing HCl ≈ er with water;
(3) mixing potassium hydrogen sulfate with NH₄OH reaction to prepare potassium sulfate ammonium salt solution Then adding potassium chloride for double decomposition reaction for 40-120min at 80-112 deg.C, and extracting to obtain potassium sulfate and ammonium chloride And the by-product of ammonium chloride NH₄Cl concentration, crystallization and centrifugal separation to prepare raw materials;
(4) reacting the absorbed tail gas HCl with barium carbonate ore for 120-240min, then performing filter pressing, processing the slag into a cement early strength agent, and crystallizing the filtrate to obtain barium chloride ；
(5)NH₄The preparation of (1): mixing calcium hydroxide to obtain 22-25 Baume slurry, mixing ammonium bicarbonate to obtain 30% solution, slowly heating to 25-89 deg.C for reaction, strongly stirring for gas-liquid separation, and absorbing the generated ammonia gas with water 。