CN102515210A

CN102515210A - Method for producing potassium bicarbonate through self-carbonization multiple-effect cross flow continues evaporation crystallization

Info

Publication number: CN102515210A
Application number: CN2011103310383A
Authority: CN
Inventors: 王国平; 钱雪明; 陈阳贵; 汪贤玉; 涂永福; 关卫军; 钱建春; 何官明; 仇玉娟; 曾邵平
Original assignee: ZHEJIANG DAYANG CHEMICAL CO Ltd
Current assignee: Zhejiang Dayang Biotech Group Co., Ltd.
Priority date: 2011-10-27
Filing date: 2011-10-27
Publication date: 2012-06-27
Anticipated expiration: 2031-10-27
Also published as: CN102515210B

Abstract

The invention discloses a method for producing potassium bicarbonate through self- carbonization multiple-effect cross flow continues evaporation crystallization, comprising the following steps: mixing a potassium bicarbonate ion exchange solution containing ammonium bicarbonate with a potassium bicarbonate mother solution containing potassium carbonate to obtain a mixed feed liquid; preheating the feed liquid, then putting the preheated feed liquid into a desorption self-carbonization tower to carrying out low temperature desorption self-carbonization; letting the feed liquid flowing out from the desorption self-carbonization tower successively enter an III-effect evaporator, an II-effect evaporator, an I-effect evaporator and an IV-effect evaporator for processing to obtain a solid-liquid mixture; separating the obtained solid-liquid mixture by a centrifugal machine to obtain potassium bicarbonate crystals and a potassium bicarbonate mother liquid containing potassium carbonate; drying and sieving the potassium bicarbonate crystals by a drying machine, and then packaging and putting in storage; and respectively putting the potassium bicarbonate mother liquid containing potassium carbonate into the II-effect evaporator and a liquid storage tank II. According to the invention, the energy consumption in the process of potassium bicarbonate evaporation can be remarkably reduced, and the particle size in the crystallization of potassium bicarbonate and the product quality are improved or controlled.

Description

Produce the method for saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization

Technical field

The present invention relates to chemical industry and resource and environment technical field, particularly relate to a kind of method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization.

Background technology

Saleratus (Potassium bicarbonate) is important industrial chemicals; Main as producing salt of wormwood, Potassium ethanoate, potassium arsenite etc.; Also be used for industries such as medicine, food, agricultural and fire-fighting medium; Saleratus is widely used as food raising agent and quality improver in recent years, and its development is more and more paid attention to.Saleratus is for producing the raw material of salt of wormwood; Salt of wormwood is widely used in industries such as chemical industry, light industry, picture tube glass bulb, pharmacy, food, welding electrode and Non-ferrous Metallurgy; Therefore the saleratus market outlook are wide, and ion exchange method and ionic membrane-electrolytic process are to produce saleratus and the main working method of salt of wormwood at present.Ion-exchange membrane electrolysis is through electrolytic chlorination potassium; At first obtain Pottasium Hydroxide and by product chlorine, Pottasium Hydroxide makes saleratus through carbonating again, and this technology has advantages such as constant product quality, save energy and three-waste pollution are few; But need be from import equipment and technology; Therefore it is big to invest radix, and return period is long, and short duration, inherent China can not promoted by big area.The process method of producing saleratus and salt of wormwood through ion exchange method has advantages such as the excellent and less investment of quality product; Manufacturing enterprise adopts by domestic majority; Once once listed in superseded technology by National Development and Reform Committee because of its three-waste pollution seriously reaches the high influence of energy consumption, domestic many enterprises therefore stopping production close or change the line of production.In recent years; Through the scientific research personnel's of enterprise research of technique, realized the IX closed cycle, solved the three-waste pollution problem; Aspect reducing energy consumption, also carry out simultaneously big quantity research; Achieve notable results, the state of the art of current ion exchange method and ion-exchange membrane electrolysis gap are constantly dwindled, and product is occupied an leading position on the market at home.

Patent CN101186317A discloses that a kind of technological equipment investment is few, energy consumption is low and the salt of wormwood preparation method of non-pollution discharge, and it feeds coal combustion flue gas or lime-kiln gas in the ammoniacal liquor behind the water dust-removal and desulfurizing, processes (NH ₄) ₂CO ₃Solution adds Ni (OH) ₂And KCl, feed ammonia and isolate Ni (NH ₃) Cl ₂Deposition, K ₂CO ₃Ammonia soln is transferred to container again, and pressurization feeds ammonia or adds liquefied ammonia, the solution layering, and the upper strata is a supersaturation ammoniacal liquor, lower floor is saturated K ₂CO ₃Contain ammonia solution, get K with extraction process ₂CO ₃Contain the ammonia saturated solution; With K ₂CO ₃Contain ammonia saturated solution heating evaporation, the deamination after-filtration falls residual NiCO ₃Back evaporate to dryness gets K ₂CO ₃Product; Ni (NH ₃) Cl ₂Water-soluble, add lime, after the heating evaporation deamination is complete, filter out Ni (OH) ₂Recycle, filtrating concentrate CaCl ₂Product, this technological operation is complicated, is difficult to realize industriallization.

Traditional ion exchange method is produced saleratus and salt of wormwood is raw material with Repone K and bicarbonate of ammonia all; Exchange through Zeo-karb; Get the saleratus exchange solution of carbonated hydrogen ammonium, then packing warehouse-in after ammonia desorb, evaporation concentration, carbonating, crystallisation by cooling, spinning and drying.Chinese patent CN200910068696.0 discloses a kind of process method of method for producing potassium carbonate by ion exchange; This technology mainly comprises unit such as desorb, evaporation, absorption, carbonating, crystallization and drying; Process step is: IX is decomposed in desorption tower after accomplishing the liquid preheating; Get into the triple effect evaporation unit then, complete evaporation of liquid gets into carbon dioxide absorption tower (is the carbonation reaction that carried out under the 0.4-0.8MPa 2-4 hour at pressure), and salt of wormwood is all turned to saleratus by carbonic acid.The used dioxide gas of carbonating is from desorption tower and moisture eliminator, and the ammonia that desorption tower decomposes is absorbed as ammoniacal liquor by the ammonia absorption tower and does dosing and use.The saleratus crystallization is carried out drying again after whizzer dries, salt of wormwood finished product packing warehouse-in.This existing ash furnace workshop section of invention cancellation has reduced environmental pollution, and it is thorough to remove non-condensable gases; Improved the evaporation heat transfer coefficient, carbonic acid gas centralized collection concentration is high, reduces the carbonating time; Improved production efficiency; Save material, reduce production costs, significantly improved economic benefit and social benefit.But this process using following current triple effect evaporation system, and vaporization temperature is higher, and steam mono-consumption is higher relatively; High temperature causes the saleratus of 12.5%-33.8% to be decomposed into salt of wormwood, influences follow-up crystallization and quality product (equipment corrosion increase iron ion content), therefore need could satisfy subsequent production through increasing the carbonating operation; Prolong production process and increased facility investment; Energy consumption also significantly increases, and its production cost is also higher relatively, the market competitiveness also a little less than.

Chinese patent CN200810164153.4 provides a kind of salt of wormwood production technique; After bicarbonate of ammonia and the IX of Repone K process, adopt decompression low temperature to evaporate to mixing solutions, thereby make to have only a spot of saleratus to be converted into salt of wormwood; The carbonic acid gas that the bicarbonate of ammonia decomposition produces in the reduction vaporization process simultaneously carries out from carbonization salt of wormwood; Thereby removed carbonation from, realized that low temperature from process for carbonization production, has reduced energy consumption; Coal consumption drops to 1.3 tons by 1.8 tons of old technology, and power consumption is reduced to 270 kilowatt-hours from 450 kilowatt-hours.Because decomposing the ammonia that produces, bicarbonate of ammonia carries out reuse in the evaporative process through being returned to ion-exchange process after absorbing; The ton product consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.25 tons and 1.60 tons and drops to 1.153 tons and 1.335 tons, has reduced corrosion on Equipment simultaneously.IX side product sodium chloride solution gets ammonium chloride product through evaporation concentration after the crystallization, solved the difficult problem of ammonia and nitrogen pollution.This technology is in medium level in the method for producing potassium carbonate by ion exchange industry, but production cost and quality product and ion-exchange membrane electrolysis also have certain gap, and most importantly steam and power consumption are high, and the product grain size number is uncontrollable.

Method for producing potassium carbonate by ion exchange and saleratus, gordian technique reduce three-waste pollution exactly and control and cut down the consumption of energy.A kind of salt of wormwood production technique that patent CN200810164153.4 provides; Through IX closed cycle and weak ammonia reuse; Basically solved the three-waste pollution problem; But the lower concentration nitrogen-containing wastewater that produces in the evaporating concentration process fails thoroughly to administer, and it adopts triple effect evaporation technology simultaneously, does not have fine solution steam mono-consumption and product quality problem.Because saleratus content low (about 14-18%) in the liquid is accomplished in IX, need large quantity of moisture is evaporated the requirement that could satisfy the back operation.Past, some small-scale producer adopted single-effect evaporation technology, and energy consumption is higher, and in scale operation, the energy consumption problem of evaporation is particularly outstanding.For save energy, just adopt multiple-effect evaporation technology can reach energy-conservation purpose.Past attempts has the people to work out the three-effect counter flow evaporation technology; Through trial run, energy-saving effect is better, but the I single-effect evaporator is owing to move under all higher severe environment of temperature, pressure and concentration; The equipment corrosion rapid speed; Also influence simultaneously quality product, the descendant has proposed triple effect following current evaporation technology scheme to the problem that exists, and has solved the problem of equipment corrosion to a great extent; But the difficult problem of steam mono-consumption is put forward again again, and how solving contradiction between power consumption and equipment and the quality product, to become the major technique of method for producing potassium carbonate by ion exchange crucial.

Chinese patent CN200710130643.8 provides a kind of multifunctional multiple-effect automatic continuous evaporative crystallization technique and crystallizer; This invention technology is: after the unsaturated aqueous solution of material or organic solvent are carried out preheating, through multiple-effect evaporator feed liquid is carried out consecutive evaporation, each temperature of imitating evaporation reduces gradually; Vacuum tightness increases gradually; When feed concentration reaches capacity, get into mold and carry out flash crystallization, the product after the crystallization carries out solid-liquid separation in whizzer, and the unsaturated solution after centrifugal is by the further evaporative crystallization of the equipment of sending back to; The water of evaporation or organic solvent recycle after cooling, realize continuous production.(1) this invention multiple-effect automatic continuous evaporative crystallization technique is said in counter-current process; Feed liquid is after the multiple-effect consecutive evaporation; Through take away pump saturated feed liquid is sent into 1st effective evaporator; And carry out pump circulation through the forced circulation pump that is located between 1st effective evaporator and the mold, and realize flash crystallization, this moment, the unsaturated aqueous solution or the organic solvent of material directly got into 2nd effect evaporator; Begin to carry out the multiple-effect consecutive evaporation from 2nd effect evaporator, 2nd effect evaporator utilizes the secondary steam of mold generation as thermal source.Its adopts the secondary steam that produces in mold flash vaporization process directly as the thermal source of 2nd effect evaporator.If the secondary steam temperature that flash crystallization produces is low; Can't satisfy the required heat requirement of 2nd effect evaporator; Say nothing of and utilize secondary steam that 2nd effect evaporator produces thermal source again as triple-effect evaporator, if it is flash vaporization point is too high, not suitable for those materials (like saleratus) that are suitable for low-temperature evaporation crystallization or thermo-sensitivity; Therefore its applicability is just restricted, let alone energy-saving and cost-reducing.(2) this invention multiple-effect automatic continuous evaporative crystallization technique is said in cross-flow technology; Feed liquid is after the multiple-effect consecutive evaporation; Through take away pump saturated feed liquid is sent into 1st effective evaporator, utilize the 2nd effect evaporator characteristic higher, saturated feed liquid is sucked 2nd effect evaporator than 1st effective evaporator vacuum tightness; And carry out pump circulation through the forced circulation pump that is located between 2nd effect evaporator and the mold; Realize flash crystallization, this moment, the unsaturated aqueous solution or the organic solution of material directly got into triple-effect evaporator, began to carry out the multiple-effect consecutive evaporation from triple effect.(3) this invention multiple-effect automatic continuous evaporative crystallization technique is said in following current technology; Feed liquid is after the multiple-effect consecutive evaporation; Directly get into the mold that is connected with last single-effect evaporator, carry out pump circulation, realize flash crystallization through the forced circulation pump that is located between this vaporizer and the mold.This following current evaporation adds continuous evaporative crystallization technique, solved since the abominable operating environment of high-temperature high concentration to the etching problem of 1st effective evaporator, but it does not have the high difficult problem of fine solution steam consumption.

Summary of the invention

The technical problem that the present invention will solve provides a kind of method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization; It can significantly reduce the energy consumption in the saleratus evaporative process; Improve or control the grain size number and the quality product of saleratus, thoroughly solve the reuse problem of lower concentration nitrogen-containing wastewater, can exempt the carbonating operation; The real purpose that realizes that recycling economy and low-carbon (LC) are produced improves the competitive edge of enterprise.

In order to solve the problems of the technologies described above; The present invention provides a kind of method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization; Comprise: saleratus mother liquor low-temperature desorption from carbonization, ammonia absorb, the saleratus multiple-effect evaporation concentrates, saleratus crystallisation by cooling, spinning and dry packing

Specifically may further comprise the steps successively:

1), setting contains the saleratus ion exchanged soln of bicarbonate of ammonia in reservoir I, and the saleratus mother liquor that contains salt of wormwood is set in reservoir II;

After containing the saleratus ion exchanged soln of bicarbonate of ammonia and containing the saleratus mother liquor mixing of salt of wormwood, get mixed liquor; Said mixed liquor relies on pump successively through vertical pipe type vapor condensation water-to-water heat exchanger and plate-type heat exchanger, feed liquid after the preheating;

2), feed liquid is carried out low-temperature desorption from carbonization through being pumped into desorb from carbonating tower after the said preheating;

3), rely on pump to get in the III single-effect evaporator from the effusive feed liquid of carbonating tower and carry out evaporation concentration from desorb;

4), the material after the III single-effect evaporator concentrates relies on to be pumped into and carries out evaporation concentration in the II single-effect evaporator;

5), the material after the II single-effect evaporator concentrates relies on to be pumped into and carries out evaporation concentration in the I single-effect evaporator;

6), the dependence of the material after the I single-effect evaporator concentrates is pumped into the IV single-effect evaporator and concentrates flash crystallization;

7), the material after the crystallization of IV single-effect evaporator carries out crystallisation by cooling through pump delivery to cooling crystallizer;

8), the solidliquid mixture behind the crystallisation by cooling separates through whizzer, the saleratus mother liquor of saleratus crystallization and carbonated potassium;

9), the saleratus crystal is packed warehouse-in after the moisture eliminator dry screened; The saleratus mother liquor of carbonated potassium is sent into II single-effect evaporator and reservoir II respectively through pump.

As improvement of producing the method for saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention:

In the saleratus ion exchanged soln that contains bicarbonate of ammonia among the reservoir I, the concentration of bicarbonate of ammonia is 40-60g/L, and the concentration of saleratus is 220-240g/L;

In the saleratus mother liquor that contains salt of wormwood among the reservoir II, the concentration of salt of wormwood is 100-120g/L, the concentration 400-440g/L of saleratus;

The saleratus ion exchanged soln that control contains bicarbonate of ammonia effusive flow velocity and contain effusive flow velocity among the saleratus mother liquor reservoir II of salt of wormwood from reservoir I; Thereby the concentration that makes bicarbonate of ammonia in the mixed liquor is 20-40g/L; The concentration of carbonated potassium is 30-60g/L, and the concentration of carbon containing potassium hydrogen phthalate is 280-320g/L.

As further improvements in methods of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention:

The secondary steam that the I single-effect evaporator produces in the step 5) is as the heating steam of step 4) II single-effect evaporator; The secondary steam that step 4) II single-effect evaporator produces is as the heating steam of step 3) III single-effect evaporator, and the secondary steam that step 3) III single-effect evaporator produces is as the heating steam of step 6) IV single-effect evaporator.

As further improvements in methods of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention: the secondary steam that the IV single-effect evaporator produces in the step 6) is divided into 2 parts:

A part extracts with after the MP steam that comes from boiler mixes, as the heating steam of step 5) I single-effect evaporator through heat pump; Said mixing back vapor pressure is controlled between the 0.004-0.006MPa;

Another part (part of promptly not taken away by heat pump) gets into vacuum system after the condensing surface cooling, control IV single-effect evaporator vacuum tightness is between negative 0.088-0.092MPa.

As further improvements in methods of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention: desorb is returned to heat power plant from the steam condensate of carbonating tower steam condensate with the generation of step 3) I single-effect evaporator step 2) in, is used as oiler feed.

As further improvements in methods of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention: step 2) desorb is connected into water-circulating pump vacuum system (clear for drawing again after carbonating tower bicarbonate of ammonia decomposes the ammonia that produces cold doubtful device cools off through plate-type heat exchanger and vertical pipe type successively; This water-circulating pump vacuum system has been done to omit in Fig. 1 and has been handled; It is between vertical pipe type condensing surface and saleratus dissolving tank); Absorb ammonia through deionized water and produce dilute ammonia solution; The steam condensate mixing that the weak ammonia that obtains behind the suction ammonia and step 4) II single-effect evaporator, step 3) III single-effect evaporator and step 6) IV single-effect evaporator produce is transported to the bicarbonate of ammonia dissolving tank, as the water of dissolving bicarbonate of ammonia raw material.

As further improvements in methods of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention: the secondary steam water of condensation of step 6) IV single-effect evaporator is delivered to ion-exchanger, cleans the resin water as ion-exchange process.

As further improvements in methods of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention: mixed liquor is after vertical pipe type vapor condensation water-to-water heat exchanger and board-like tail gas heat exchanger preheating in the step 1); Temperature of charge rises to 50 ℃ by 35 ℃; Steam condensate in the vertical pipe type vapor condensation water-to-water heat exchanger is from the steam condensate of desorb from carbonating tower steam condensate and the generation of step 3) I single-effect evaporator, and the tail gas in the said board-like tail gas heat exchanger decomposes the secondary steam from carbonization produced from desorb from carbonating tower.Above-mentioned these can be as the utilization again of secondhand energy.

As further improvements in methods of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention: I single-effect evaporator temperature is controlled at 85-87 ℃; II single-effect evaporator temperature is controlled at 73-75 ℃; III single-effect evaporator temperature is controlled at 63-65 ℃, and IV single-effect evaporator temperature is controlled at 53-59 ℃;

I single-effect evaporator vacuum degree control is at negative pressure 0.056-0.060MPa; II single-effect evaporator vacuum degree control is at negative pressure 0.070-0.074MPa; III single-effect evaporator vacuum degree control is at negative pressure 0.078-0.082MPa, and IV single-effect evaporator vacuum degree control is at negative pressure 0.088-0.092MPa.

As further improvements in methods of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention: I single-effect evaporator, II single-effect evaporator and III single-effect evaporator are the vertical pipe type falling-film evaporator, and the IV single-effect evaporator is a DTB type continuous evaporative crystallization device.

Under above-mentioned industry control control of the present invention:

I single-effect evaporator discharging feed liquid carbonated hydrogen ammonium is 6-10g/L, and carbonated potassium is 70-110g/L, and the carbon containing potassium hydrogen phthalate is 460-520g/L; II single-effect evaporator discharging feed liquid carbonated hydrogen ammonium is 8-12g/L, and carbonated potassium is 30-60g/L, and the carbon containing potassium hydrogen phthalate is 380-440g/L; III single-effect evaporator discharging feed liquid carbonated hydrogen ammonium is 12-16g/L, and carbonated potassium is 30-50g/L, and the carbon containing potassium hydrogen phthalate is 340-380g/L; IV single-effect evaporator discharging feed liquid carbonated hydrogen ammonium is 5-8g/L; Carbonated potassium 80-120g/L, carbon containing potassium hydrogen phthalate 480-540g/L, solid-to-liquid ratio is about 10-18% (mass ratio).

Step 2) described decomposition is from 60-65 ℃ of carbonating tower temperature control, and vacuum degree control is at negative pressure 0.078-0.082MPa, and vapor pressure is controlled at 0.4MPa; Through low-temperature decomposition after carbonization; Material carbonated hydrogen ammonium 14-18g/L, salt of wormwood 20-30g/L, saleratus 300-340g/L.

The said cooling crystallizer of step 7) carries out crystallisation by cooling, and temperature of charge is reduced to 45 ℃ by 53-59 ℃, and solid-to-liquid ratio rises to 18-26% by 10-18%.

The centrifugal gained saleratus of step 8) crystallization mean particle size is greater than 2.0mm, and saleratus content is greater than 99.1%.

In the present invention; The centrifugal gained saleratus of step 8) mother liquor is sneaked into the II single-effect evaporator carry out evaporation concentration; Wherein the mother liquor of preferred 35-75% is admitted to the II single-effect evaporator; More preferably the mother liquor of 45-75% is admitted to the II single-effect evaporator, and the mother liquor that most preferably is 55-65% is admitted to the II single-effect evaporator.

In the present invention, through regulating step 5) in I single-effect evaporator heating steam pressure control material temperature in the vaporizer, and then, realize control or improve saleratus grain size number and production quality control the adjustment of material Tc in the IV single-effect evaporator.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of method of the present invention is 0.68 ton, and power consumption is 220 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.141 tons and 1.316 tons.

Operational path of the present invention is summed up as follows: with carbonated hydrogen ammonium is 40-60g/L; The carbon containing potassium hydrogen phthalate is the saleratus solvent of 220-240g/L and carbonated potassium wherein is 100-120g/L; The saleratus mother liquor of carbon containing potassium hydrogen phthalate 400-440g/L mixes; Control that carbonated hydrogen ammonium is 20-40g/L in the mixed material, carbonated potassium is 30-60g/L, and the carbon containing potassium hydrogen phthalate is 280-320g/L; Mixed material gets into the vertical pipe type tail gas heat exchanger successively through pump and board-like vapor condensation water-to-water heat exchanger carries out preheating, and temperature of charge rises to 50 ℃ by 35 ℃ after the preheating; Feed liquid is carried out low-temperature desorption from carbonization through being pumped into desorb from carbonating tower after preheating; Decomposition is from 60-65 ℃ of carbonating tower temperature control; Vacuum degree control is at 0.078-0.082MPa, and vapor pressure is controlled at 0.4MPa, through decomposing the material carbonated hydrogen ammonium 14-18g/L after carbonization; Salt of wormwood 20-30g/L, saleratus 300-340g/L; Decomposition feed liquid after carbonization is squeezed into the III single-effect evaporator through pump and is carried out evaporation concentration; 63-65 ℃ of III single-effect evaporator temperature control; Vacuum degree control is negative pressure 0.078-0.082MPa; Carbonated hydrogen ammonium is 12-16g/L in the material of concentrated back, and carbonated potassium is 30-50g/L, and the carbon containing potassium hydrogen phthalate is 340-380g/L; Material after the III single-effect evaporator concentrates carries out evaporation concentration through being pumped into the II single-effect evaporator; 73-75 ℃ of II single-effect evaporator temperature control; Vacuum degree control is at negative pressure 0.070-0.074MPa; Carbonated hydrogen ammonium is 8-12g/L in the material of concentrated back, and carbonated potassium is 30-60g/L, and the carbon containing potassium hydrogen phthalate is 380-440g/L; Material after the II single-effect evaporator concentrates carries out evaporation concentration through being pumped into the I single-effect evaporator; 85-87 ℃ of I single-effect evaporator temperature control; Vacuum degree control is at negative pressure 0.056-0.060MPa, and vapor pressure is controlled at 0.004-0.006MPa, and carbonated hydrogen ammonium is 6-10g/L in the material of concentrated back; Carbonated potassium is 70-110g/L, and the carbon containing potassium hydrogen phthalate is 460-520g/L; Material after the I single-effect evaporator concentrates carries out the consecutive evaporation condensing crystal through being pumped into the IV single-effect evaporator; 53-59 ℃ of IV single-effect evaporator temperature control; Vacuum degree control is at 0.088-0.092MPa, and carbonated hydrogen ammonium is 5-8g/L in the material of concentrated back, carbonated potassium 80-120g/L; Carbon containing potassium hydrogen phthalate 480-540g/L, solid-to-liquid ratio is about 10-18% (mass ratio); Material after the IV single-effect evaporator concentrates carries out crystallisation by cooling through pump delivery to cooling crystallizer, and temperature is reduced to 45 ℃ by 53-59 ℃, and solid-to-liquid ratio rises to 22-26% (mass ratio) by 14-18% (mass ratio); Solidliquid mixture behind the crystallisation by cooling separates through whizzer, gets the saleratus mother liquor of saleratus crystallization and carbonated potassium; Centrifugal gained saleratus crystal is packed warehouse-in after dry screened; The saleratus mother liquor of centrifugal gained carbonated potassium requires to send into II single-effect evaporator or mother liquor reservoir respectively through pump according to processing parameter; Wherein the mother liquor of preferred 35-75% is admitted to the II single-effect evaporator; More preferably the mother liquor of 45-75% is admitted to the II single-effect evaporator; The mother liquor that most preferably is 55-65% is admitted to the II single-effect evaporator; The mother liquor that is admitted in the II single-effect evaporator dilutes and heat effect through feed liquid, and a large amount of tiny crystalline particles have been improved the grain size number of follow-up saleratus by dissolving again in the mother liquor.

Method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention; The saleratus mother liquor of carbonated potassium is through carrying out low-temperature desorption from carbonization in desorption tower; Exempt follow-up carbonating operation, also improved the quality of product when significantly reducing production energy consumption.

As a kind of method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention; Can be through regulating step 5) in I single-effect evaporator (13) heating steam pressure control material temperature in the vaporizer; And then controlled step 6) Tc of IV single-effect evaporator (15) material realizes saleratus crystallization particle diameter and quality are controlled.

The present invention adopts quadruple effect continuous evaporative crystallization system; End through heat pump extracts in the IV single-effect evaporator is imitated steam and is come from the heating steam of the HP steam mixed steam of boiler as the I single-effect evaporator; The secondary steam that the I single-effect evaporator produces is as the heating steam of II single-effect evaporator; The secondary steam that the II single-effect evaporator produces is as the heating steam of III single-effect evaporator; The secondary steam that the III single-effect evaporator produces has improved steam utilization efficient as the heating steam of IV single-effect evaporator, significantly reduces energy consumption.

Annotate: so-called " steam is imitated at the end " is exactly to adopt the secondary steam that last effect produces in the multiple-effect evaporator, in general all is through the vacuum system discharging, do not utilize again; And so-called " secondary steam " is exactly in the evaporator evaporation process, because the secondary steam that solvent evaporation produced, so-called multiple-effect evaporation utilizes secondary steam more exactly and is achieved.

The present invention will decompose in carbonating tower bicarbonate of ammonia and decompose the ammonia that produces and be connected into the water-circulating pump system again after through the interchanger cooling; Absorb ammonia through deionized water and produce dilute ammonia solution; Inhale the weak ammonia and step 4) II single-effect evaporator (11), step 3) III single-effect evaporator (9) and step 6) IV single-effect evaporator (15) mixing that obtain behind the ammonia and be transported to the bicarbonate of ammonia dissolving tank; As the water of dissolving bicarbonate of ammonia raw material, the utilization ratio that has improved bicarbonate of ammonia has also reduced environmental pollution simultaneously.

The present invention produces desorb from the steam condensate of carbonating tower and I single-effect evaporator steam condensate return to heat power plant as oiler feed; The secondary steam water of condensation that the IV single-effect evaporator produces is delivered to ion-exchange process; As the ion exchange resin water for cleaning; Present technique is that boiler and ion-exchange process provide good water sources, has also solved the pollution difficult problem of lower concentration nitrogen-containing wastewater simultaneously.

In a word, the present invention compares with common process, has exempted carbonation, and cancellation ash furnace workshop section has reduced the required energy consumption of environmental pollution and carbonation; Adopt quadruple effect continuous evaporative crystallization system; Extract end effect secondary steam and come from of the heating steam of the HP steam mixed steam of boiler through heat pump as the I single-effect evaporator; The secondary steam that the I single-effect evaporator produces is as the heating steam of II single-effect evaporator; The secondary steam that the II single-effect evaporator produces is as the heating steam of III single-effect evaporator, and the secondary steam that the III single-effect evaporator produces comprises that as the heating steam of IV single-effect evaporator the heat in the steam condensate also effectively utilizes; Significantly improve steam utilization efficient, reduced energy consumption; Through the adjustment of I single-effect evaporator heating steam pressure, controlled material temperature in the vaporizer, and then, realized control or improve saleratus grain size number and production quality control the adjustment of material Tc in the IV single-effect evaporator; The weak ammonia that produces in desorb and the evaporative process is as the water of dissolving bicarbonate of ammonia raw material, and the utilization ratio that has improved bicarbonate of ammonia has also reduced environmental pollution simultaneously; Steam condensate and lower concentration nitrogen-containing wastewater fully utilize as oiler feed and ion-exchange process cleaning resin water as heat power plant respectively; For boiler and ion-exchange process provide good water sources, also solved the pollution difficult problem of lower concentration nitrogen-containing wastewater simultaneously.Method from carbonization multiple-effect cross-flow continuous evaporative crystallization production salt of wormwood of the present invention is a kind of green production technique, has both reduced energy consumption, improves quality product again, reduces environmental pollution simultaneously, is worth large-scale promotion application.

Description of drawings

Do further explain below in conjunction with the accompanying drawing specific embodiments of the invention.

Fig. 1 is a method process flow sheet of producing salt of wormwood from carbonization multiple-effect cross-flow continuous evaporative crystallization of the present invention.

Embodiment

Fig. 1 has provided a kind of device from carbonization multiple-effect cross-flow continuous evaporative crystallization production saleratus, comprises that reservoir I1, reservoir II2, pump 3, vertical pipe type vapor condensation water-to-water heat exchanger 4, plate-type heat exchanger 5, pump 6, desorb are from the cold doubtful device 27 of carbonating tower 7, pump 8, III single-effect evaporator 9, pump 10, II single-effect evaporator 11, pump 12, I single-effect evaporator 13, pump 14, IV single-effect evaporator 15, pump 16, cooling crystallizer 17, whizzer 18, moisture eliminator 19, pump 20, heat pump 21, condensing surface 22, vacuum system 23, boiler 24, bicarbonate of ammonia dissolving tank 25, ion-exchanger 26 and vertical pipe type.

The outlet of said reservoir I1 is connected with the opening for feed of reservoir II2, and the discharge port of reservoir II2 links to each other with the inlet of vertical pipe type vapor condensation water-to-water heat exchanger 4 through pipeline 101, on pipeline 101, is provided with pump 3.

4 outlets of vertical pipe type vapor condensation water-to-water heat exchanger link to each other with the inlet of plate-type heat exchanger 5, and inlet is connected from the top of carbonating tower 7 with desorb through pipeline 103 in the outlet of plate-type heat exchanger 5; Desorb is connected with plate-type heat exchanger 5 through pipeline 102 from the top exit of carbonating tower 7.

Desorb is connected through the opening for feed of pipeline 104 with III single-effect evaporator 9 from the material outlet of carbonating tower 7, and the discharge port of III single-effect evaporator 9 is connected through the opening for feed of pipeline 105 with II single-effect evaporator 11, on pipeline 105, is provided with pump 10.The discharge port of II single-effect evaporator 11 is connected through the feeding mouth of pipeline 106 with I single-effect evaporator 13, on pipeline 106, is provided with pump 12; The discharge port of I single-effect evaporator 13 is connected through the feeding mouth of pipeline 107 with IV single-effect evaporator 15, on pipeline 107, is provided with pump 14, and the discharge port of IV single-effect evaporator 15 links to each other with the inlet of cooling crystallizer 17 through pipeline 118, on pipeline 118, is provided with pump 16.The outlet of cooling crystallizer 17 links to each other with the inlet of whizzer 18; The solid outlet of whizzer 18 is connected with moisture eliminator 19, and the liquid exit of whizzer 18 links to each other with reservoir II2 with II single-effect evaporator 11 respectively through behind the pipeline 119; At pipeline 119 pump 20 is set.

The secondary steam that I single-effect evaporator 13 produces passes to the heating steam of II single-effect evaporator 11 as II single-effect evaporator 11 through pipeline 108; The secondary steam that II single-effect evaporator 11 produces passes to the heating steam of III single-effect evaporator 9 as III single-effect evaporator 9 through pipeline 109; The secondary steam that III single-effect evaporator 9 produces passes to the heating steam of the IV single-effect evaporator 15 of IV single-effect evaporator 15 conducts through pipeline 110.

The secondary steam that IV single-effect evaporator 15 produces is divided into 2 parts:

A part is mixed the back through heat pump 21 extractions and is passed to I single-effect evaporator 13 through pipeline 111 with the MP steam that comes from boiler 24, as the heating steam of I single-effect evaporator 13; Another part (part of promptly not taken away by heat pump 21) gets in the condensing surface 22 through pipeline 112; After condensing surface 22 coolings, get into vacuum system 23; Vacuum system 23 (clear for drawing that link to each other with IV single-effect evaporator 15; This structure has been done to omit in Fig. 1 and has been handled), the vacuum tightness of vacuum system 23 control IV single-effect evaporators 15.

Desorb is returned to heat power plant through pipeline 113 from the steam condensate of carbonating tower 7, as boiler 24 feedwater; In like manner, the steam condensate that I single-effect evaporator 13 produces returns to heat power plant through pipeline 113, as boiler 24 feedwater.

Desorb exports successively from the gas of carbonating tower 7 (for ammonia), and pipeline 102 links to each other with plate-type heat exchanger 5; Plate-type heat exchanger 5 (is a device between cold doubtful device 27 of vertical pipe type and bicarbonate of ammonia dissolving tank 25 through being connected into the water-circulating pump vacuum system again after cold doubtful device 27 coolings of vertical pipe type again; Clear for drawing; In Fig. 1, done to omit and handled); The water-circulating pump vacuum system absorbs ammonia through deionized water and produces dilute ammonia solution, inhales the weak ammonia that obtains behind the ammonia and is transported to bicarbonate of ammonia dissolving tank 25.Simultaneously; The steam condensate that IV single-effect evaporator 15 produces all is transported to bicarbonate of ammonia dissolving tank 25 through the steam condensate that pipeline 115, III single-effect evaporator 9 produce through pipeline 116 through the steam condensate that pipeline 114, II single-effect evaporator 11 produce, as the water (this strand water is as the preparation purposes of IX raw material ammonium bicarbonate soln) of dissolving bicarbonate of ammonia raw material.

Condensing surface 22 links to each other with ion-exchanger 26 through pipeline 117, thereby makes the secondary steam water of condensation of IV single-effect evaporator 15 be sent to ion-exchanger 26, cleans the resin water as ion-exchange process.

Steam condensate in the vertical pipe type vapor condensation water-to-water heat exchanger 4 is from the steam condensate of desorb from carbonating tower 7 steam condensates and 13 generations of step 3I single-effect evaporator, the secondary steam that the tail gas in the board-like tail gas heat exchanger 5 decomposes from carbonization produced from carbonating tower 7 from desorb.It is used as reusing of energy source.

Embodiment 1, a kind of method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization, carry out following steps successively:

1, the saleratus ion exchanged soln that contains bicarbonate of ammonia is set in reservoir I1, the concentration of bicarbonate of ammonia is 50g/L, and the concentration of saleratus is 230g/L; All the other are water.

The saleratus mother liquor that contains salt of wormwood is set in reservoir II2; The concentration of salt of wormwood is 120g/L, the concentration 420g/L of saleratus; All the other are water.

After above-mentioned saleratus ion exchanged soln and saleratus mother liquor mix according to 5: 2 volume flow ratio, mixed liquor; Carbonated hydrogen ammonium 30g/L in the mixed liquor, carbonated potassium 50g/L, carbon containing potassium hydrogen phthalate 280g/L.

Mixed liquor gets in vertical pipe type vapor condensation water-to-water heat exchanger 4 and the plate-type heat exchanger 5 through pipeline 101 under the effect of pump 3 successively, feed liquid after the preheating; Feed liquid rises to 50 ℃ of (notes: 35 ℃ of temperature that refer to the original mixed feed liquid) by 35 ℃ after the preheating.

Steam condensate in the vertical pipe type vapor condensation water-to-water heat exchanger 4 is from the steam condensate of desorb from carbonating tower 7 steam condensates and 13 generations of step 3I single-effect evaporator, the secondary steam that the tail gas in the board-like tail gas heat exchanger 5 decomposes from carbonization produced from carbonating tower 7 from desorb.Said process carries out through pipeline 102 and pipeline 113 respectively.

2, feed liquid is carried out low-temperature desorption from carbonization sending into desorb through pipeline 103 under the effect of pump 6 after the board-like tail gas heat exchanger 5 effusive preheatings in carbonating tower 7; Desorb is controlled 60-65 ℃ from the temperature of carbonating tower 7, and vacuum degree control is at 0.078-0.082MPa, and vapor pressure is controlled at 0.4MPa.

Through desorb from the decomposition of carbonating tower 7 after carbonizing treatment, from desorb carbonated hydrogen ammonium 16g/L from carbonating tower 7 effusive feed liquids, salt of wormwood 30g/L, saleratus 320g/L.

3, under the effect of pump 8, get in the III single-effect evaporators 9 from carbonating tower 7 effusive feed liquids from desorb and carry out evaporation concentration through pipeline 104;

63-65 ℃ of the temperature control of III single-effect evaporator 9, vacuum degree control concentrate carbonated hydrogen ammonium 14g/L in the back material (i.e. material after III single-effect evaporator 9 concentrates), salt of wormwood 40g/L, saleratus 360g/L at negative pressure 0.078-0.082MPa;

4, the material dependence pump 10 after III single-effect evaporator 9 concentrates is sent into through pipeline 105 and is carried out evaporation concentration in the II single-effect evaporator 11;

73-75 ℃ of the temperature control of II single-effect evaporator 11, vacuum degree control concentrate carbonated hydrogen ammonium 10g/L in the back material (material after II single-effect evaporator 11 concentrates), salt of wormwood 60g/L, saleratus 440g/L at negative pressure 0.070-0.074MPa;

5, the material dependence pump 12 after II single-effect evaporator 11 concentrates is sent into through pipeline 106 and is carried out evaporation concentration in the I single-effect evaporator 13;

85-87 ℃ of I single-effect evaporator 13 temperature control; Vacuum degree control is at negative pressure 0.056-0.060MPa, and vapor pressure is controlled at 0.004-0.006MPa, concentrates carbonated hydrogen ammonium 8g/L in the back material (i.e. material after I single-effect evaporator 13 concentrates); Salt of wormwood 110g/L, saleratus 510g/L.

Explain: control material temperature in the I single-effect evaporator 13 through the heating steam pressure (being vapor pressure) of regulating I single-effect evaporator 13; Thereby realize adjustment, realize control or improve saleratus grain size number and production quality control material Tc in the IV single-effect evaporator 15.Be specially: when the heating steam pressure of I single-effect evaporator 13 increased, the material Tc will raise in the IV single-effect evaporator 15, and the saleratus grain size number can reduce, and quality product can reduce; Otherwise when the heating steam pressure of I single-effect evaporator 13 reduced, the material Tc will reduce in the IV single-effect evaporator 15, and the saleratus grain size number can increase, and quality product can improve;

6, the material after I single-effect evaporator 13 concentrates relies on pump 14 to send into IV single-effect evaporator 15 through pipeline 107 and concentrates flash crystallization;

53-56 ℃ of the temperature control of IV single-effect evaporator 15; Vacuum degree control concentrates carbonated hydrogen ammonium 6g/L in the back material (being that IV single-effect evaporator 15 concentrates the back material), salt of wormwood 120g/L at negative pressure 0.088-0.092MPa; Saleratus 540g/L, solid-to-liquid ratio is about 18% (mass ratio);

7, the material behind IV single-effect evaporator 15 condensing crystals is transported to cooling crystallizer 17 through pipeline 118 and carries out crystallisation by cooling under the effect of pump 16;

Thereby make material temperature be reduced to 45 ℃ by 53-56 ℃, solid-to-liquid ratio rises to 28% (mass ratio) by 18% (mass ratio).

8, the solidliquid mixture behind the crystallisation by cooling separates (the control centrifugal rotational speed is 1200 rev/mins) through whizzer 18, gets the saleratus mother liquor (salt of wormwood content is 120g/L, and saleratus is 440g/L) of saleratus crystallization and carbonated potassium.

Saleratus crystallization mean particle size is greater than 2.0mm, and saleratus content is 99.1%, meets national premium grads quality standard.

9, the saleratus crystal is packed warehouse-in after moisture eliminator 19 dry screened; The saleratus mother liquor of carbonated potassium is divided into 2 the tunnel through pipeline 119 under the effect of pump 20: 75% volume is sent into II single-effect evaporator 11 carry out evaporating, concentrating and crystallizing once more, 25% volume sends into that to carry out step 1) preparation among the reservoir II2 used.

Annotate: just can realize guaranteeing the centrifugal component content consistence of " the saleratus mother liquor " and " saleratus mother liquor " among the reservoir II2 of gained afterwards according to above-mentioned control process parameters.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of aforesaid method is 0.683 ton, and power consumption is 224 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.141 tons and 1.319 tons.

Embodiment 2, a kind of method (workflow is with embodiment 1) of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization:

Steam condensate in the vertical pipe type vapor condensation water-to-water heat exchanger 4 is from the steam condensate of desorb from carbonating tower 7 steam condensates and 13 generations of step 3I single-effect evaporator, the secondary steam that the tail gas in the board-like tail gas heat exchanger 5 decomposes from carbonization produced from carbonating tower 7 from desorb.

73-75 ℃ of the temperature control of II single-effect evaporator 11, vacuum degree control concentrate carbonated hydrogen ammonium 10g/L in the back material (material after II single-effect evaporator 11 concentrates), salt of wormwood 55g/L, saleratus 420g/L at negative pressure 0.070-0.074MPa;

85-87 ℃ of I single-effect evaporator 13 temperature control; Vacuum degree control is at negative pressure 0.056-0.060MPa, and vapor pressure is controlled at 0.004-0.006MPa, concentrates carbonated hydrogen ammonium 7g/L in the back material (i.e. material after I single-effect evaporator 13 concentrates); Salt of wormwood 100g/L, saleratus 500g/L.

Explain: control material temperature in the I single-effect evaporator 13 through the heating steam pressure (being vapor pressure) of regulating I single-effect evaporator 13; Thereby realize adjustment, realize control or improve saleratus grain size number and production quality control material Tc in the IV single-effect evaporator 15.Be specially: when the heating steam pressure of I single-effect evaporator 13 increased, the material Tc will raise in the IV single-effect evaporator 15, and the saleratus grain size number can reduce, and quality product can reduce; Otherwise when the heating steam pressure of I single-effect evaporator 13 reduced, the material Tc will reduce in the IV single-effect evaporator 15, and the saleratus grain size number can increase, and quality product can improve.

53-56 ℃ of the temperature control of IV single-effect evaporator 15; Vacuum degree control concentrates carbonated hydrogen ammonium 7g/L in the back material (being that IV single-effect evaporator 15 concentrates the back material), salt of wormwood 110g/L at negative pressure 0.088-0.092MPa; Saleratus 530g/L, solid-to-liquid ratio is about 16% (mass ratio);

Thereby make material temperature be reduced to 45 ℃ by 53-56 ℃, solid-to-liquid ratio rises to 24% (mass ratio) by 16% (mass ratio).

8, the solidliquid mixture behind the crystallisation by cooling separates (the control centrifugal rotational speed is 1200 rev/mins) through whizzer 18, gets the saleratus mother liquor (salt of wormwood content is 110g/L, and saleratus is 440g/L) of saleratus crystallization and carbonated potassium.

Centrifugal gained saleratus crystallization mean particle size is greater than 2.0mm, and saleratus content is 99.2%, meets national premium grads quality standard.

9, the saleratus crystal is packed warehouse-in after moisture eliminator 19 dry screened; The saleratus mother liquor of carbonated potassium is divided into 2 the tunnel through pipeline 119 under the effect of pump 20: 65% volume is sent into II single-effect evaporator 11 carry out evaporating, concentrating and crystallizing once more, 35% volume sends into that to carry out step 1) preparation among the reservoir II2 used.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of aforesaid method is 0.678 ton, and power consumption is 218 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.139 tons and 1.319 tons.

Embodiment 3: a kind of method (workflow is with embodiment 1) of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization:

73-75 ℃ of the temperature control of II single-effect evaporator 11, vacuum degree control concentrate carbonated hydrogen ammonium 10g/L in the back material (material after II single-effect evaporator 11 concentrates), salt of wormwood 45g/L, saleratus 410g/L at negative pressure 0.070-0.074MPa;

85-87 ℃ of I single-effect evaporator 13 temperature control; Vacuum degree control is at negative pressure 0.056-0.060MPa, and vapor pressure is controlled at 0.004-0.006MPa, concentrates carbonated hydrogen ammonium 7g/L in the back material (i.e. material after I single-effect evaporator 13 concentrates); Salt of wormwood 90g/L, saleratus 490g/L.

53-56 ℃ of the temperature control of IV single-effect evaporator 15; Vacuum degree control concentrates carbonated hydrogen ammonium 6g/L in the back material (being that IV single-effect evaporator 15 concentrates the back material), salt of wormwood 75g/L at negative pressure 0.088-0.092MPa; Saleratus 530g/L, solid-to-liquid ratio is about 16% (mass ratio);

8, the solidliquid mixture behind the crystallisation by cooling separates (the control centrifugal rotational speed is 1200 rev/mins) through whizzer 18, gets the saleratus mother liquor (salt of wormwood content is 75g/L, and saleratus is 450g/L) of saleratus crystallization and carbonated potassium.

Centrifugal gained saleratus crystallization mean particle size is greater than 2.0mm, and saleratus content is 99.3%, meets national premium grads quality standard.

9, the saleratus crystal is packed warehouse-in after moisture eliminator 19 dry screened; The saleratus mother liquor of carbonated potassium is divided into 2 the tunnel through pipeline 119 under the effect of pump 20: 55% volume is sent into II single-effect evaporator 11 carry out evaporating, concentrating and crystallizing once more, 45% volume sends into that to carry out step 1) preparation among the reservoir II2 used.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of aforesaid method is 0.68 ton, and power consumption is 220 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.141 tons and 1.316 tons.

Embodiment 4: a kind of method (workflow is with embodiment 1) of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization:

73-75 ℃ of the temperature control of II single-effect evaporator 11, vacuum degree control concentrate carbonated hydrogen ammonium 10g/L in the back material (material after II single-effect evaporator 11 concentrates), salt of wormwood 40g/L, saleratus 400g/L at negative pressure 0.070-0.074MPa;

85-87 ℃ of I single-effect evaporator 13 temperature control; Vacuum degree control is at negative pressure 0.056-0.060MPa, and vapor pressure is controlled at 0.004-0.006MPa, concentrates carbonated hydrogen ammonium 7g/L in the back material (i.e. material after I single-effect evaporator 13 concentrates); Salt of wormwood 80g/L, saleratus 470g/L.

53-56 ℃ of the temperature control of IV single-effect evaporator 15; Vacuum degree control concentrates carbonated hydrogen ammonium 6g/L in the back material (being that IV single-effect evaporator 15 concentrates the back material), salt of wormwood 85g/L at negative pressure 0.088-0.092MPa; Saleratus 500g/L, solid-to-liquid ratio is about 14% (mass ratio);

Thereby make material temperature be reduced to 45 ℃ by 53-56 ℃, solid-to-liquid ratio rises to 20% (mass ratio) by 14% (mass ratio).

8, the solidliquid mixture behind the crystallisation by cooling separates (the control centrifugal rotational speed is 1200 rev/mins) through whizzer 18, gets the saleratus mother liquor (salt of wormwood content is 80g/L, and saleratus is 430g/L) of saleratus crystallization and carbonated potassium.

Centrifugal gained saleratus crystallization mean particle size is greater than 2.0mm, and saleratus content is 99.4%, meets national premium grads quality standard.

9, the saleratus crystal is packed warehouse-in after moisture eliminator 19 dry screened; The saleratus mother liquor of carbonated potassium is divided into 2 the tunnel through pipeline 119 under the effect of pump 20: 45% volume is sent into II single-effect evaporator 11 carry out evaporating, concentrating and crystallizing once more, 55% volume sends into that to carry out step 1) preparation among the reservoir II2 used.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of aforesaid method is 0.688 ton, and power consumption is 228 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.141 tons and 1.322 tons.

Embodiment 5: a kind of method (workflow is with embodiment 1) of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization:

73-75 ℃ of the temperature control of II single-effect evaporator 11, vacuum degree control concentrate carbonated hydrogen ammonium 12g/L in the back material (material after II single-effect evaporator 11 concentrates), salt of wormwood 35g/L, saleratus 380g/L at negative pressure 0.070-0.074MPa;

85-87 ℃ of I single-effect evaporator 13 temperature control; Vacuum degree control is at negative pressure 0.056-0.060MPa, and vapor pressure is controlled at 0.004-0.006MPa, concentrates carbonated hydrogen ammonium 7g/L in the back material (i.e. material after I single-effect evaporator 13 concentrates); Salt of wormwood 70g/L, saleratus 460g/L.

53-56 ℃ of the temperature control of IV single-effect evaporator 15; Vacuum degree control concentrates carbonated hydrogen ammonium 6g/L in the back material (being that IV single-effect evaporator 15 concentrates the back material), salt of wormwood 80g/L at negative pressure 0.088-0.092MPa; Saleratus 490g/L, solid-to-liquid ratio is about 10% (mass ratio);

Thereby make material temperature be reduced to 45 ℃ by 53-56 ℃, solid-to-liquid ratio rises to 18% (mass ratio) by 10% (mass ratio).

8, the solidliquid mixture behind the crystallisation by cooling separates (the control centrifugal rotational speed is 1200 rev/mins) through whizzer 18, gets the saleratus mother liquor (salt of wormwood content is 80g/L, and saleratus is 440g/L) of saleratus crystallization and carbonated potassium.

Centrifugal gained saleratus crystallization mean particle size is 2.0mm, and saleratus content is 99.6%, meets national premium grads quality standard.

9, the saleratus crystal is packed warehouse-in after moisture eliminator 19 dry screened; The saleratus mother liquor of carbonated potassium is divided into 2 the tunnel through pipeline 119 under the effect of pump 20: 35% volume is sent into II single-effect evaporator 11 carry out evaporating, concentrating and crystallizing once more, 65% volume sends into that to carry out step 1) preparation among the reservoir II2 used.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of aforesaid method is 0.688 ton, and power consumption is 231 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.140 tons and 1.323 tons.

Embodiment 6: a kind of method (workflow is with embodiment 1) of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization:

After above-mentioned saleratus ion exchanged soln and saleratus mother liquor mix according to 1: 1 volume flow ratio, mixed liquor; Carbonated hydrogen ammonium 25g/L in the mixed liquor, carbonated potassium 60g/L, carbon containing potassium hydrogen phthalate 320g/L.

Through desorb from the decomposition of carbonating tower 7 after carbonizing treatment, from desorb carbonated hydrogen ammonium 15g/L from carbonating tower 7 effusive feed liquids, salt of wormwood 45g/L, saleratus 340g/L.

63-65 ℃ of the temperature control of III single-effect evaporator 9, vacuum degree control concentrate carbonated hydrogen ammonium 12g/L in the back material (i.e. material after III single-effect evaporator 9 concentrates), salt of wormwood 55g/L, saleratus 380g/L at negative pressure 0.078-0.082MPa;

73-75 ℃ of the temperature control of II single-effect evaporator 11, vacuum degree control concentrate carbonated hydrogen ammonium 10g/L in the back material (material after II single-effect evaporator 11 concentrates), salt of wormwood 65g/L, saleratus 410g/L at negative pressure 0.070-0.074MPa;

85-87 ℃ of I single-effect evaporator 13 temperature control; Vacuum degree control is at negative pressure 0.056-0.060MPa, and vapor pressure is controlled at 0.004-0.006MPa, concentrates carbonated hydrogen ammonium 6g/L in the back material (i.e. material after I single-effect evaporator 13 concentrates); Salt of wormwood 85g/L, saleratus 460g/L.

53-56 ℃ of the temperature control of IV single-effect evaporator 15; Vacuum degree control concentrates carbonated hydrogen ammonium 5g/L in the back material (being that IV single-effect evaporator 15 concentrates the back material), salt of wormwood 90g/L at negative pressure 0.088-0.092MPa; Saleratus 520g/L, solid-to-liquid ratio is about 15% (mass ratio);

Thereby make material temperature be reduced to 45 ℃ by 53-56 ℃, solid-to-liquid ratio rises to 13% (mass ratio) by 15% (mass ratio).

Centrifugal gained saleratus crystallization mean particle size is 2.0mm, and saleratus content is 99.2%, meets national premium grads quality standard.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of aforesaid method is 0.682 ton, and power consumption is 219 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.141 tons and 1.318 tons.

Embodiment 7: a kind of method (workflow is with embodiment 1) of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization:

After above-mentioned saleratus ion exchanged soln and saleratus mother liquor mix according to 4: 1 volume flow ratio, mixed liquor; Carbonated hydrogen ammonium 40g/L in the mixed liquor, carbonated potassium 30g/L, carbon containing potassium hydrogen phthalate 270g/L.

Through desorb from the decomposition of carbonating tower 7 after carbonizing treatment, from desorb carbonated hydrogen ammonium 20g/L from carbonating tower 7 effusive feed liquids, salt of wormwood 15g/L, saleratus 300g/L.

63-65 ℃ of the temperature control of III single-effect evaporator 9, vacuum degree control concentrate carbonated hydrogen ammonium 16g/L in the back material (i.e. material after III single-effect evaporator 9 concentrates), salt of wormwood 18g/L, saleratus 330g/L at negative pressure 0.078-0.082MPa;

73-75 ℃ of the temperature control of II single-effect evaporator 11, vacuum degree control concentrate carbonated hydrogen ammonium 14g/L in the back material (material after II single-effect evaporator 11 concentrates), salt of wormwood 25g/L, saleratus 370g/L at negative pressure 0.070-0.074MPa;

85-87 ℃ of I single-effect evaporator 13 temperature control; Vacuum degree control is at negative pressure 0.056-0.060MPa, and vapor pressure is controlled at 0.004-0.006MPa, concentrates carbonated hydrogen ammonium 12g/L in the back material (i.e. material after I single-effect evaporator 13 concentrates); Salt of wormwood 35g/L, saleratus 450g/L.

53-56 ℃ of the temperature control of IV single-effect evaporator 15; Vacuum degree control concentrates carbonated hydrogen ammonium 10g/L in the back material (being that IV single-effect evaporator 15 concentrates the back material), salt of wormwood 40g/L at negative pressure 0.088-0.092MPa; Saleratus 490g/L, solid-to-liquid ratio is about 10% (mass ratio);

8, the solidliquid mixture behind the crystallisation by cooling separates (the control centrifugal rotational speed is 1200 rev/mins) through whizzer 18, gets the saleratus mother liquor (salt of wormwood content is 55g/L, and saleratus is 420g/L) of saleratus crystallization and carbonated potassium.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of aforesaid method is 0.688 ton, and power consumption is 230 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.143 tons and 1.324 tons.

Embodiment 8: a kind of method (workflow is with embodiment 1) of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization:

59 ℃ of the temperature controls of IV single-effect evaporator 15; Vacuum degree control concentrates carbonated hydrogen ammonium 6g/L in the back material (being that IV single-effect evaporator 15 concentrates the back material), salt of wormwood 75g/L at negative pressure 0.088-0.092MPa; Saleratus 530g/L, solid-to-liquid ratio is about 14% (mass ratio);

Thereby make material temperature be reduced to 45 ℃ by 59 ℃, solid-to-liquid ratio rises to 24% (mass ratio) by 14% (mass ratio).

Centrifugal gained saleratus crystallization mean particle size is greater than 1.2mm, and saleratus content is 99.1%, meets national premium grads quality standard.

Adopting the coal consumption (the mark coal calculates) of 1 ton of salt of wormwood of the every production of aforesaid method is 0.684 ton, and power consumption is 226 kilowatt-hours, and the consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.141 tons and 1.321 tons.

The comparative example

Comparative Examples 1, the potassium bicarbonate solution of the carbonated hydrogen ammonium in the reservoir (1) and the saleratus mother liquor of the carbonated potassium in the reservoir (2) are mixed (carbonated hydrogen ammonium 30g/L in the mixed material; Carbonated potassium 50g/L; Carbon containing potassium hydrogen phthalate 280g/L), the potassium bicarbonate solution of mixture is produced by existing technology (patent of invention CN200810164153.4 is said), and the coal consumption of 1 ton of salt of wormwood of every production (the mark coal calculates) is 1.3 tons; Power consumption is 270 kilowatt-hours; The consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.153 tons and 1.335 tons, and evaporation gained saleratus median size is less than 1mm, and saleratus content is on average less than 99.0%.

Comparative Examples 2, the potassium bicarbonate solution of the carbonated hydrogen ammonium in the reservoir (1) and the saleratus mother liquor of the carbonated potassium in the reservoir (2) are mixed (carbonated hydrogen ammonium 30g/L in the mixed material; Carbonated potassium 50g/L; Carbon containing potassium hydrogen phthalate 280g/L), mixed material is produced by embodiment 3 of the present invention, and gained saleratus crystallization mean particle size is greater than 2.0mm; Saleratus content is 99.3%; Meet national premium grads quality standard, the coal consumption of 1 ton of salt of wormwood of every production (the mark coal calculates) is 0.68 ton, and power consumption is 220 kilowatt-hours; The consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.141 tons and 1.316 tons, and comprehensive cost reduces more than 800 yuan than existing production technique.

The process method of Comparative Examples 3, the described a kind of method for producing potassium carbonate by ion exchange of patent CN200910068696.0; This technology mainly comprises unit such as desorb, evaporation, absorption, carbonating, crystallization and drying; Concrete process step is: IX is decomposed in desorption tower after accomplishing the liquid preheating; Get into triple effect then and steam the unit; Complete evaporation of liquid gets into carbon dioxide absorption tower (is the carbonation reaction that carried out under the 0.4-0.8MPa 2-4 hour at pressure), and salt of wormwood is all turned to saleratus by carbonic acid.The used dioxide gas of carbonating is from desorption tower and moisture eliminator, and the ammonia that desorption tower decomposes is absorbed as ammoniacal liquor by the ammonia absorption tower and does dosing and use.The saleratus crystallization is carried out drying again after whizzer dries, salt of wormwood finished product packing warehouse-in.Patent CN200910068696.0 has cancelled existing ash furnace workshop section, has reduced environmental pollution, and it is thorough to remove non-condensable gases; Improved the evaporation heat transfer coefficient, carbonic acid gas centralized collection concentration is high, reduces the carbonating time; Improved production efficiency; Save material, reduce production costs, significantly improved economic benefit and social benefit.

Patent CN200910068696.0 technology and compared with techniques of the present invention, they are to adopt following current triple effect evaporation system, vaporization temperature is higher; Steam mono-consumption is high; High temperature causes the saleratus of 12.5%-33.8% to be decomposed into salt of wormwood, influences follow-up crystallization and quality product (equipment corrosion increase iron ion content), need could satisfy subsequent production through increasing the carbonating operation; Therefore prolonged production process and increased facility investment, energy consumption also significantly increases.And the present invention adopts quadruple effect cross-flow continuous evaporative crystallization, extracts end effect secondary steam and gives birth to the heating of vapour mixture as the I vaporizer through heat pump, has significantly reduced steam consumption; The present invention simultaneously adopts DBT type continuous evaporative crystallization device; Improve the grain size number (the average crystallite granularity is greater than 2mm) of saleratus, adopt low-temperature decomposition, reduce the ratio of salt of wormwood in the saleratus from the carbonization technology; Improve the quality of products; Also cancel the carbonating operation, reduced power consumption significantly, shortened the PT (the required carbonating time of the described production salt of wormwood of patent CN200910068696.0 method is 2-4 hour).

According to the described method of CN200910068696.0; The coal consumption of 1 ton of salt of wormwood of every production (the mark coal calculates) is 0.88 ton; Power consumption is 290 kilowatt-hours; The consumption of main raw material Repone K and bicarbonate of ammonia is respectively 1.19 tons and 1.38 tons, and evaporation gained saleratus median size is less than 2mm, and saleratus content is on average less than 99.1%.

At last, it is also to be noted that what more than enumerate only is several specific embodiments of the present invention.Obviously, the invention is not restricted to above embodiment, many distortion can also be arranged.All distortion that those of ordinary skill in the art can directly derive or associate from content disclosed by the invention all should be thought protection scope of the present invention.

Claims

1. produce the method for saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization, it is characterized in that may further comprise the steps successively:

1), setting contains the saleratus ion exchanged soln of bicarbonate of ammonia in reservoir I (1), and the saleratus mother liquor that contains salt of wormwood is set in reservoir II (2);

After the said saleratus ion exchanged soln that contains bicarbonate of ammonia mixes with the saleratus mother liquor that contains salt of wormwood, get mixed liquor; Said mixed liquor relies on pump (3) successively through vertical pipe type vapor condensation water-to-water heat exchanger (4) and plate-type heat exchanger (5), must preheating after feed liquid;

2), feed liquid is sent into desorb through pump (6) and is carried out low-temperature desorption from carbonization from carbonating tower (7) after the said preheating;

3), rely on pump (8) to get in the III single-effect evaporator (9) from the effusive feed liquid of carbonating tower (7) and carry out evaporation concentration from desorb;

4), the dependence pump of the material after III single-effect evaporator (9) concentrates (10) is sent in the II single-effect evaporator (11) and is carried out evaporation concentration;

5), the dependence pump of the material after II single-effect evaporator (11) concentrates (12) is sent in the I single-effect evaporator (13) and is carried out evaporation concentration;

6), the material after I single-effect evaporator (13) concentrates relies on pump (14) to send into IV single-effect evaporator (15) and concentrates flash crystallization;

7), the material after IV single-effect evaporator (15) crystallization is transported to cooling crystallizer (17) through pump (16) and carries out crystallisation by cooling;

8), the solidliquid mixture behind the crystallisation by cooling separates through whizzer (18), the saleratus mother liquor of saleratus crystallization and carbonated potassium;

9), the saleratus crystal is packed warehouse-in after moisture eliminator (19) dry screened; The saleratus mother liquor of carbonated potassium is sent into II single-effect evaporator (11) and reservoir II (2) respectively through pump (20).

2. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 1 is characterized in that:

In the saleratus ion exchanged soln that contains bicarbonate of ammonia among the said reservoir I (1), the concentration of bicarbonate of ammonia is 40-60g/L, and the concentration of saleratus is 220-240g/L;

In the saleratus mother liquor that contains salt of wormwood among the said reservoir II (2), the concentration of salt of wormwood is 100-120g/L, the concentration 400-440g/L of saleratus;

The saleratus ion exchanged soln that control contains bicarbonate of ammonia effusive flow velocity and contain effusive flow velocity among the saleratus mother liquor reservoir II (2) of salt of wormwood from reservoir I (1); Thereby the concentration that makes bicarbonate of ammonia in the mixed liquor is 20-40g/L; The concentration of carbonated potassium is 30-60g/L, and the concentration of carbon containing potassium hydrogen phthalate is 280-320g/L.

3. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 2 is characterized in that:

The secondary steam that I single-effect evaporator (13) produces in the step 5) is as the heating steam of step 4) II single-effect evaporator (11); The secondary steam that step 4) II single-effect evaporator (11) produces is as the heating steam of step 3) III single-effect evaporator (9), and the secondary steam that step 3) III single-effect evaporator (9) produces is as the heating steam of step 6) IV single-effect evaporator (15).

4. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 3 is characterized in that: the secondary steam that IV single-effect evaporator (15) produces in the step 6) is divided into 2 parts:

A part extracts with after the MP steam that comes from boiler (24) mixes, as the heating steam of step 5) I single-effect evaporator (13) through heat pump (21); Said mixing back vapor pressure is controlled between the 0.004-0.006MPa;

Another part gets into vacuum system (23) after condensing surface (22) cooling, control IV single-effect evaporator (15) vacuum tightness is between negative 0.088-0.092MPa.

5. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 4; It is characterized in that: step 2) in desorb return to heat power plant from the steam condensate that carbonating tower (7) steam condensate and step 3) I single-effect evaporator (13) produce, feed water as boiler (24).

6. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 5; It is characterized in that: step 2) desorb is connected into the water-circulating pump vacuum system again after the ammonia that carbonating tower (7) bicarbonate of ammonia decompose to produce cools off through plate-type heat exchanger (5) and the cold doubtful device of vertical pipe type (27) successively; Absorb ammonia through deionized water and produce dilute ammonia solution; The steam condensate mixing that the weak ammonia that obtains behind the suction ammonia and step 4) II single-effect evaporator (11), step 3) III single-effect evaporator (9) and step 6) IV single-effect evaporator (15) produce is transported to bicarbonate of ammonia dissolving tank (25), as the water of dissolving bicarbonate of ammonia raw material.

7. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 6; It is characterized in that: the secondary steam water of condensation of step 6) IV single-effect evaporator (15) is delivered to ion-exchanger (26), cleans the resin water as ion-exchange process.

8. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 7; It is characterized in that: mixed liquor is after vertical pipe type vapor condensation water-to-water heat exchanger (4) and board-like tail gas heat exchanger (5) preheating in the step 1); Temperature of charge rises to 50 ℃ by 35 ℃; Steam condensate in the described vertical pipe type vapor condensation water-to-water heat exchanger (4) is from the steam condensate of desorb from carbonating tower (7) steam condensate and step 3) I single-effect evaporator (13) generation, and the tail gas in the said board-like tail gas heat exchanger (5) decomposes the secondary steam from carbonization produced from desorb from carbonating tower (7).

9. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 8 is characterized in that:

I single-effect evaporator (13) temperature is controlled at 85-87 ℃, and II single-effect evaporator (11) temperature is controlled at 73-75 ℃, and III single-effect evaporator (9) temperature is controlled at 63-65 ℃, and IV single-effect evaporator (15) temperature is controlled at 53-59 ℃;

I single-effect evaporator (13) vacuum degree control is at negative pressure 0.056-0.060MPa; II single-effect evaporator (11) vacuum degree control is at negative pressure 0.070-0.074MPa; III single-effect evaporator (9) vacuum degree control is at negative pressure 0.078-0.082MPa, and IV single-effect evaporator (15) vacuum degree control is at negative pressure 0.088-0.092MPa.

10. method of producing saleratus from carbonization multiple-effect cross-flow continuous evaporative crystallization according to claim 9; It is characterized in that: I single-effect evaporator (13), II single-effect evaporator (11) and III single-effect evaporator (9) are the vertical pipe type falling-film evaporator, and IV single-effect evaporator (15) is a DTB type continuous evaporative crystallization device.