CN1031359A - From carnallite, produce the method for Repone K and Cardia Salt - Google Patents

Abstract

This disclosure of the Invention a kind of method of from carnallite, producing Repone K and Cardia Salt product.Adopt the size of certain method control carnallitite granularity, again with the otherness form the basis on NaCl crystal, carnallitite crystal, the KCl crystal equigranular, adopt the method for mechanical grading, carry out preliminary purification, it is simple that it has technical process, produces power consumption and lack, and product cost is low, three-waste free pollution, advantage such as the utilization of resources is reasonable.Adopt the excessive cold cut method of condensing crystal again and again again, further improved the performance of Repone K product.

Description

From carnallite, produce the method for Repone K and Cardia Salt

The invention belongs to field of inorganic chemical engineering.

The carnallite that chloride type potassium magnesium salts bittern makes through natural evaporative crystallization, with the technology that carnallite is produced Repone K, what adopt the earliest is the thermosol crystallization process.Arrived the fifties, the thermosol crystallization process is replaced by cold decomposition-flotation-washing technology gradually.Arrive the eighties, adopted cold cut-cold crystallization technology progressively to replace cold decomposition-flotation-washing technology abroad.But the details of cold cut-cold crystallization technology is not appeared in the newspapers.The carnallite that present domestic coastal area makes from seawater, the method that is reprocessed into the employing of Repone K product is the thermosol crystallization process, and this method power consumption is high, and facility investment is big, thereby the production cost height.The Potassium process that the Qinghai potash fertilizer plant adopts is the cold decomposition of carnallite-flotation-washing technology.This method will adopt flotation reagent, so there is following shortcoming: the one, this flotation reagent costs an arm and a leg; The 2nd, take away a large amount of KCl in the flotation mother liquor, and this part KCl reclaims difficulty, cause the rate of recovery of Repone K to reduce; The 3rd, flotation mother liquor comprehensive utilization difficulty, and make production environment seriously polluted; The 4th and since process using flotation reagent, so in the KCl product, also contain some this flotation reagent, make quality product low, re-workability is poor; The 5th, the energy consumption height, product thickening filtration difficulty, initial cost is big, shortcomings such as production cost height.

The purpose of this invention is to provide a kind of novel process of from carnallite, producing Repone K and Cardia Salt product.It is simple that it has technology, and the building equipment less investment need not to add any flotation reagent in the technological process, the quality product height, and production cost is low, the rate of recovery height of KCl, non-environmental-pollution is to series of advantages such as the carnallite utilization of resources is reasonable.

The theoretical foundation that the present invention adopts is a particle size study.Find that in the process of research carnallite granularity the granularity of general carnallitite is all greater than NaCl crystalline granularity in the carnallite, NaCl crystalline granularity is again all greater than KCl crystalline granularity in the thick potassium.According to above this principle, thereby established theoretical basis of the present invention.This invention is adopted the crystal size by various components in the carnallite to vary in size to carry out mechanical grading, can remove 60～80% NaCl impurity, and the KCl content in the carnallite is effectively improved, adopt cold decomposition again, part NaCl particle is removed in screening for the second time, just can obtain purified KCl product through operations such as evaporation concentration, filtrations again.And after screening the NaCl impurity removed, through the hydrocyclone concentration, fine grain after sedimentation as mine tailing comprehensive utilization (simple herein) again again, and coarse grained because of containing a spot of KCl crystal, unnecessary MgCl is removed in washing after filtration ₂After can obtain the Cardia Salt product.

Figure (1) is a process flow sheet of the present invention.

Requirement for carnallite is: the granularity in the carnallite is lower than 20% less than other content of 0.5 grade. Reach the requirement of mechanical grading for the granularity that makes carnallite, the method that adopts is with the complete carnallite of for the first time crystallization, bleed off old halogen, 0.5～1.5 times new halogen putting into again for the first time crystallization carnallite bittern enters crystallizing pond, make carnallite continue crystallization, to be crystallized complete, bleed off again the carnallite that old halogen can obtain meeting the requirements. After this carnallite and old halogen mix (solid-to-liquid ratio is 1: 5～15), through the screening of screening I, the screening I adopt vibratory sieve or recoil dusting cover all can, sieve diameter is 0.2～2 millimeter. After screening I screening, solid (major part be NaCl) and bittern below the sieve aperture with "-" expression, the solid above the sieve aperture (major part is carnallite), use "+" to represent. Carnallite after for the first time screening adds fresh water and carries out cold decomposition, makes MgCl in the carnallite₂Dissolving, the fresh water amount that adds of cold decomposition is greater than the theoretical value amount. After decomposing, the crystal size of KCl is far smaller than the granularity of NaCl crystal, owing to there is a large amount of NaCl to exist in the rework solution, so single crystalline NaCl does not have dissolving substantially in the solid, its granule size is also less than what big variation, through screening II operation mechanical grading, remove most of NaCl remaining in the solid again, the screening II adopts cyclone, recoil dusting cover and the vibratory sieve all can (sieve diameter is 0.2～2 millimeter. Solid on sieve aperture is the NaCl solid substantially, and below sieve aperture then is KCl crystal and decomposition nut liquid substantially. Remove clear liquid bittern (returning salt pan carnallite processed) through the sedimentation operation again, the solid after concentrating and bittern is washing procedure after filtration, removes remaining MgCl₂With part NaCl impurity, the fresh water amount that adds is 25～50% of amount of solid, filtrate and washing lotion are returned the salt pan and are produced carnallite, solid (being also referred to as the intermediate products of KCl) after the washing adds the fresh water cold cut more after filtration, namely add excessive fresh water amount and all dissolve NaCl in the solid, the addition of fresh water be the theoretical value amount of water 120～200% between, and then evaporative crystallization, remove unnecessary moisture content in the dissolving NaCl process, this process crystallization just occurred as control terminal point (NaCl content is as 15.5～16.0% in the liquid) take NaCl, the KCl product that can obtain making with extra care after filtration again, the mother liquor after the filtration uses as cold decomposition water. Fine particle solid and bittern after the screening of screening I carry out concentration by hydrocyclone, and fine grained and bittern are after sedimentation, and bittern returns the screening I as the circulation halogen of screening I operation, and mine tailing fully utilizes as other chemical products. Coarse grained after filtration washing can obtain the Cardia Salt product, and the fresh water amount of adding determines that by the requirement of Cardia Salt product the bittern behind the filtration washing returns salt pan salt manufacturing and carnallite is used.

This technological process is compared with other technological process, has following advantage: one, good product quality. Do not add in process of production any organic and inorganic reagent, thereby the product purity height, and particle property might as well. Two, technological process is simple, and the building equipment small investment is so production cost is low. Three, more reasonable to the utilization of resources, three-waste free pollution, and the rate of recovery of KCl is also higher.

Embodiment: sample is got 4.0 tons of the carnallites in Qinghai potash fertilizer plant first dressing-works.Consisting of of carnallite: KCl19.92%; NaCl22.37%; MgCl ₂Be 27.18%; Other insolubles is 2.13%.

Experiment process is shown in figure (1).The screening I adopts the screening of XSG5-74 type wet type fine sizing machine, and the treatment capacity of sieve apparatus is a 188.5Kg/ rice ²The time, sieve diameter is 0.5 millimeter, as delivery medium, solid-to-liquid ratio is 1: 10 to the screening I with the old halogen in salt pan.The fresh water amount of cold decomposition is 520Kg, and the amount of water of filtration washing is 200Kg, and the amount of water of cold cut is 1288Kg, and the sieve diameter of screening II is 0.373 millimeter.Solid below screening I screening orbital canal,posterior internal, the fresh water that adds in the filtration washing process is 400Kg.Obtain the smart potassium of 646Kg at last, the Cardia Salt product of 492Kg.

Example 2: potash fertilizer plant salt pan, Qinghai carnallite granularity is thinner, takes this carnallite is mixed the measure that continues evaporative crystallization with equivalent KCl bittern, and-0.52 millimeter level drops to 15.29% from 59.4% in the ore.Carnallite each component concentration KCl19.86%, NaCl14.64%, MgCl after the increase granularity ₂28.69%.With flow process and the condition identical with example 1, the high-quality Repone K product production that makes is 15.16% of the processing carnallite, and Cardia Salt output is 10.55% of the processing carnallite.

Claims (3)

1, a kind ofly produce the method for Repone K and Cardia Salt product with carnallite as raw material, it comprises operations such as cold decomposition, sedimentation, filtration washing, cold cut, hydrocyclone concentrate, and it is characterized in that:

A. this process using screening operation makes sodium chloride crystal with the carnallitite crystal separately; Sodium-chlor is separated with potassium chloride;

B. control the method for carnallitite particle property in this technology, the carnallitite that adopts crystallization for the first time to finish bleeds off old halogen, puts into 0.5～1.5 times new halogen of the carnallitite of crystallization for the first time bittern again, makes carnallitite continue crystallization, and to be crystallized finishing bleeds off its old halogen again;

C. the method that improves Repone K product granularity characteristic in this technology is the intermediates with Repone K, adds excessive fresh water dissolution and falls wherein impurity, removes excessive moisture content through evaporation again, and the potassium chloride granularity is increased.

2, method according to claim 1, the sieve diameter that it is characterized in that sieving operation is 0.2～2 millimeter.

3, method according to claim 1, it is characterized in that improving Repone K product granularity characteristic, to add excessive fresh water amount be 20～100% of theoretical value.

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