CN1706748A

CN1706748A - Potassium chloride and calcium nitrate double decomposing-freezing process of producing potassium nitrate

Info

Publication number: CN1706748A
Application number: CN 200410049426
Authority: CN
Inventors: 唐尚文
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-06
Filing date: 2004-06-06
Publication date: 2005-12-14

Abstract

The present invention is the process of double decomposing calcium nitrate solution and potassium chloride and freezing to produce potassium nitrate and co-product calcium chloride. Compared with available technology, the present invention has the advantages of short technological process, simple apparatus, high product purity, high potassium chloride converting rate, low power consumption, low production cost, etc. Calcium nitrate is produced with dilute nitric acid and ground limestone through reaction and has low cost, and the limestone may be replaced with other calcium source material for further lowered cost.

Description

The method that Repone K, nitrocalcite metathesis-cold method are produced saltpetre

The present invention relates to a kind of method of producing saltpetre, particularly can provide a kind of economy, fast, the method for environmental protection, high efficiency production high purity saltpetre, belong to field of fine chemical.

Saltpetre is a kind of broad-spectrum Chemicals, is mainly used in fields such as war industry, glass-ceramic industry, health care, foodstuffs industry.Simultaneously also be the high-quality chemical fertilizer of a kind of hypersorption, pollution-free, noresidue, contain nitric nitrogen 17%, potassium oxide 46%.Be used for cash crop and green agricultural product,, can increase substantially the yield and quality of farm crop as fruits and vegetables, tobacco, flowers etc.

Prior art is produced saltpetre and is mainly contained three kinds of methods:

1. Repone K and SODIUMNITRATE double decomposition;

2. Repone K and Xiao Suan double decomposition;

3. Repone K and Xiao Suan ion exchange method;

Method 1 cost height; Method 2 complex process, unstable product quality, Repone K transformation efficiency are low; Method 3 equipment complexity; Technical process are long; Need often regeneration or change ion exchange resin; Thereby production cost is also high.2; 3 environmental pollutions of while method are big; And byproduct Lvization utilization ratio is not high; And concentration process is serious to equipment corrosion

Application number is 95115710 Chinese invention patent, adopts rare nitric acid, Repone K and magnesium oxide double decomposition, 10---30 ℃ of of of of of of crystallization goes of through be refrigerated to-a out saltpetre.Compare with aforesaid method, simplified technical process, reduced production cost.But the by-product utilization ratio is not high, and after employing Tan precipitated light magnesium, mother liquor Lvization still was difficult to handle.

Drawback such as the present invention is directed to prior art cost height, equipment is many, technology is long, pollution is big, energy consumption is high, the Repone K transformation efficiency is low, the by-product utilization rate is low adopts Repone K and nitrocalcite preparing potassium nitrate by means of double decomposition.Its ultimate principle is: utilize calcium chloride and the saltpetre huge difference of solubleness at a lower temperature, first crystallization goes out saltpetre, continues to concentrate production calcium chloride then.Its principle technical process is:

1. slowly add limestone powder in rare nitric acid, very economical ground obtains the bigger ca nitrate soln of concentration under the normal temperature and pressure;

2. in ca nitrate soln, add the Repone K of design flow, under 20-40 ℃ of temperature, Repone K is all dissolved;

3. removal of impurities, filtration or decant are removed residue;

4. concentrated slightly in case of necessity, to finite concentration, be cooled to room temperature;

5. be refrigerated to 0--20 ℃, saltpetre is separated out in crystallization, solid-liquid separation, and the cold water washing crystal obtains high pure nitric acid potassium product;

6. the mother liquor condensing crystal obtains by-product calcium chloride;

7. can be earlier remove impurity magnesium chloride in the industrial potassium chloride (solution), then with by the ca nitrate soln metathesis that rare nitric acid and the reaction of high-purity limestone powder generate, obtain higher saltpetre and the high-purity calcium chloride of attached product of purity through freezing and crystallizing with salt of wormwood;

8. also can directly in rare nitric acid, add Repone K, limestone powder,, produce saltpetre and calcium chloride then through removal of impurities, filtration, freezing and crystallizing, solid-liquid separation, condensing crystal.

Compared with the prior art, the invention has the advantages that:

1. primary crystallization can obtain stay-in-grade high pure nitric acid potassium product;

2. Repone K transformation efficiency height;

3. by-product calcium chloride is of many uses, and is in demand;

4. equipment is simple, and technical process is few, and production cost is low;

5. energy consumption is low in the production process;

6. there is not equipment corrosion; No waste gas, waste water, waste residue environmental pollution.

Used limestone powder in this patent can be high-purity Wingdale (as calcium carbide limestone, system sode ash rock etc.) powder, also can be common lime stone (as the cement limestone etc.) powder; Can use unslaked lime (CaO) or white lime [Ca (OH) ₂] the replacement limestone powder; Also can replace limestone powder with other calcium source (fine particle calcium carbonate, coarse whiting, carbide slag or the lime carbonate that is transformed by phosphogypsum etc.).

Example 1.HNO ₃(60%) 110g adds H ₂O 300ml adds KCl (100%) 73g, CaCO ₃(high-purity limestone powder) 200 order 50g, gentle agitation 15 minutes, filtering and impurity removing is refrigerated to-15 ℃, and crystallization goes out transparent minute hand shape KNO ₃Crystal 123g (moisture), decant, the cold water washing crystal is analyzed KNO ₃Content 99.8%; Mother liquor concentrate white CaCl ₂.2H ₂O.

Claims

1. claim 1. method of producing saltpetre is characterized in that: nitrocalcite (solution) and Repone K multiple (solution) with design flow decompose, and by removal of impurities, freezing, first Crystallization Separation goes out saltpetre, concentrates then to produce calcium chloride.

2. it is characterized in that according to claim 1: ca nitrate soln reacts generation by rare nitric acid (15-60%) and limestone powder under normal temperature and pressure conditions.

3. it is characterized in that according to claim 1: nitrocalcite and Repone K replacement(metathesis)reaction liquid through purifying, under proper concn, 0---crystallization goes out high pure nitric acid potassium under 20 ℃ of temperature condition, isolates the mother liquor after the potassium nitrate crystals, through concentrated, crystallization, generate Calcium dichloride dihydrate or Calcium Chloride Powder Anhydrous.

4. it is characterized in that according to claim 1-2: the limestone powder that is used to generate ca nitrate soln can be with high-purity limestone (as calcium carbide limestone, system sode ash rock etc.), also can form through grinding with common limestone (as the cement limestone etc.).

5. it is characterized in that according to claim 1-2: above-mentioned limestone powder can be used unslaked lime (CaO) or white lime [Ca (OH) ₂] replace; Also can be with other calcium source (transform to form lime carbonate etc.) replacement as light calcium carbonate powder, dicalcium powder, carbide slag or by phosphogypsum.

6. it is characterized in that according to claim 1-3: can directly in rare nitric acid (10-60%), add Repone K and limestone powder (or other calcium source), through metathesis, removal of impurities, freezing generation saltpetre and calcium chloride.