CN100439249C

CN100439249C - Process for producing sodium sulfate and sodium chloride in Na2SO4-NaCl-H2O system

Info

Publication number: CN100439249C
Application number: CNB2006101140438A
Authority: CN
Inventors: 彭赛军
Original assignee: China Zhongqing International Engineering Co Ltd
Current assignee: China Medium Light International Engineering Co., Ltd.; Hongze Yinzhu Chemical Industry Group Co., Ltd.
Priority date: 2006-10-25
Filing date: 2006-10-25
Publication date: 2008-12-03
Anticipated expiration: 2026-10-25
Also published as: CN1944256A

Abstract

The process of producing sodium sulfate and sodium chloride in a Na2SO4-NaCl-H2O system belongs to the field of mixed inorganic solution evaporating separation technology. Mixed solution of sodium sulfate and sodium chloride as material is first evaporated and then separated to obtain sodium sulfate, sodium chloride and evaporated mother liquor; the evaporated mother liquor is low temperature evaporated and separated to obtain sodium chloride and salt-making mother liquor; and the salt-making mother liquor is evaporated and separated to obtain sodium sulfate and saltpeter-making mother liquor. The present invention has the features of high main and side product quality, high material adaptability, low cost, low cost, no waste draining, etc.

Description

From Na 2SO 4--NaCl-H 2Produce the technology of sodium sulfate and sodium-chlor in the O system

Technical field

The invention belongs to the evaporation separation technology field of inorganic salt mixing solutions, refer to a kind of especially from NaCl-Na ₂SO ₄-H ₂Produce the technology of sodium sulfate and sodium-chlor in the O system.

Background technology

Known from Na ₂SO ₄--NaCl-H ₂Produce the method for sodium sulfate and sodium-chlor in the O system, have the salt-making mother liquor of evaporation absorption method and evaporation system nitre mother liquor to discharge method, require Na in the raw material but wherein evaporate the existence of salt-making mother liquor absorption method ₂SO ₄Content less than the content of NaCl, and wherein evaporation system nitre mother liquor discharge method exists and requires Na in the raw material ₂SO ₄Content low and influence problem of environment more than content, the raw material rate of recovery of NaCl, therefore, above-mentioned two methods are difficult to adapt to Na ₂SO ₄--NaCl-H ₂O system sodium sulfate and sodium chloride content change situation greatly.

Summary of the invention

The present invention is directed to the problems referred to above, change Na ₂SO ₄--NaCl-H ₂The O system is produced the technology of sodium sulfate and sodium-chlor, proposes one and can adapt to Na ₂SO ₄--NaCl-H ₂The variation of O system sodium sulfate and sodium chloride content cuts down the consumption of energy and cost, solves the sodium sulfate and the sodium-chlor production technique of environment protection.

For achieving the above object, the present invention takes following design: a kind of from Na ₂SO ₄--NaCl-H ₂Produce the technology of sodium sulfate and sodium-chlor in the O system, it is characterized in that it comprises the following steps:

One, gets Na ₂SO ₄--NaCl-H ₂O system raw material, wherein concentration of component is: NaCl 5-320g/l, Na ₂SO ₄5-350g/l evaporates above-mentioned system raw material, and vaporization temperature 60-130 ℃, carry out solid-liquid separation then and obtain sodium sulfate or sodium-chlor and mother liquid evaporation in the raw material, the mother liquid evaporation concentration of component is: NaCl 305-290g/l, Na ₂SO ₄50-60g/l;

Two, the above-mentioned mother liquid evaporation of low-temperature evaporation and carry out solid-liquid separation and obtain salt-making mother liquor and sodium-chlor, vaporization temperature 40-60 ℃, the salt-making mother liquor concentration of component is: NaCl 295-285g/l, Na ₂SO ₄60-70g/l;

Three, the above-mentioned salt-making mother liquor of evaporation and carry out solid-liquid separation and obtain making nitre mother liquor and sodium sulfate, vaporization temperature is 5-15 ℃ or 70-100 ℃, system nitre mother liquor concentration of component is: NaCl 290-320g/l, Na ₂SO ₄20-60g/l;

Four, this system nitre mother liquor participates in the above-mentioned low-temperature evaporation salt manufacturing operation of circulation down.

Na ₂SO ₄--NaCl-H ₂Can contain concentration in the O system for greater than 0 calcium sulfate and/or the sal epsom that is less than or equal to 5g/l.

Advantage of the present invention is: the present invention be one from Na ₂SO ₄--NaCl-H ₂Produce the technology of sodium sulfate and sodium-chlor in the O system, at first take Na ₂SO ₄--NaCl-H ₂O system raw material, wherein component concentration is: NaCl5-320g/l, Na ₂SO ₄5-350g/l evaporates above-mentioned raw materials, and vaporization temperature 60-130 ℃, the mother liquid evaporation concentration of component is: NaCl 305-290g/l, Na ₂SO ₄50-60g/l carries out solid-liquid separation then and obtains sodium sulfate or sodium-chlor and mother liquid evaporation in the raw material, and the above-mentioned mother liquid evaporation of low-temperature evaporation is NaCl 295-285g/l, Na up to the salt-making mother liquor concentration of component then ₂SO ₄60-70g/l carries out solid-liquid separation again and obtains salt-making mother liquor and sodium-chlor, vaporization temperature 40-60 ℃; The above-mentioned salt-making mother liquor of revaporization up to system nitre mother liquor concentration of component is: NaCl290-320g/l, Na ₂SO ₄51.6-60g/l, to carry out solid-liquid separation again and obtain making nitre mother liquor and sodium sulfate, vaporization temperature is 5-15 ℃ or 70-100 ℃; At last, this system nitre mother liquor participates in the low-temperature evaporation salt manufacturing operation in above-mentioned second step of circulation down.In the above-mentioned technological process, the theoretical rate of recovery of sodium sulfate and sodium-chlor is 100%, and the rate of recovery of discharging method 50-90% than known technology evaporation system nitre mother liquor has significantly raising, and the acceptable end product standard that the product sodium sulfate quality reaches country's promulgation (contains Na ₂SO ₄〉=99%, Cl ^-≤ 0.35%), the product sodium-chlor quality premium grads standard that reaches country promulgation (contains NaCl 〉=99.1%, SO ₄ ^2-≤ 0.30%).Technological process does not have waste liquid and discharges, and has the high and quality product height of raw material availability, and energy consumption is low, production cost is low and characteristics such as three-waste free discharge.

Embodiment

Embodiment 1: a kind of from Na ₂SO ₄--NaCl-H ₂Produce the technology of sodium sulfate and sodium-chlor in the O system, comprise the following steps:

One, gets 100m ³Na ₂SO ₄--NaCl-H ₂O system raw material, wherein concentration of component is: NaCl 300g/l, Na ₂SO ₄20g/l evaporates above-mentioned bittern, and 68 ℃ of vaporization temperatures are carried out solid-liquid separation then and obtained 19.3 tons in sodium-chlor and mother liquid evaporation 36.4m ³, the mother liquid evaporation concentration of component is: NaCl 294g/l, Na ₂SO ₄55g/l;

Two, above-mentioned mother liquid evaporation of low-temperature evaporation and circulation system nitre mother liquor and carry out solid-liquid separation and obtain salt-making mother liquor 156.3m ³With 10.7 tons in sodium-chlor, 48 ℃ of vaporization temperatures, the salt-making mother liquor concentration of component is: NaCl 290g/l, Na ₂SO ₄64g/l;

Three, the above-mentioned salt-making mother liquor of evaporation and carry out solid-liquid separation and obtain making nitre mother liquor 148.1m ³With 2.0 tons in sodium sulfate, 95 ℃ of vaporization temperatures, system nitre mother liquor concentration of component is: NaCl 306g/l, Na ₂SO ₄54g/l, this system nitre mother liquor participates in the low-temperature evaporation salt manufacturing operation in above-mentioned second step of circulation down.

Embodiment 2: a kind of from Na ₂SO ₄--NaCl-H ₂Produce the technology of sodium sulfate and sodium-chlor in the O system, comprise the following steps:

One, gets 100m ³NaCl-Na ₂SO ₄-H ₂O system raw material, wherein concentration of component is: NaCl 179g/l, Na ₂SO ₄181g/l evaporates above-mentioned raw materials, and 63 ℃ of vaporization temperatures are carried out solid-liquid separation then and obtained 14.5 tons in sodium sulfate and mother liquid evaporation 62.1m in the raw material ³, the mother liquid evaporation concentration of component is: NaCl 290g/l, Na ₂SO ₄56g/l;

Two, above-mentioned mother liquid evaporation of low-temperature evaporation and circulation system nitre mother liquor and carry out solid-liquid separation and obtain salt-making mother liquor 247.5m ³With 18 tons in sodium-chlor, 45 ℃ of vaporization temperatures, the salt-making mother liquor concentration of component is: NaCl 286g/l, Na ₂SO ₄68g/l;

Three, the above-mentioned salt-making mother liquor of evaporation and carry out solid-liquid separation and obtain making nitre mother liquor 185.4m ³With 3.5 tons in sodium sulfate, 100 ℃ of vaporization temperatures, system nitre mother liquor concentration of component is: NaCl 310g/l, Na ₂SO ₄55g/l, this system nitre mother liquor participates in the low-temperature evaporation salt manufacturing operation in above-mentioned second step of circulation down.

Embodiment 3: a kind of from Na ₂SO ₄--NaCl-H ₂Produce the technology of sodium sulfate and sodium-chlor in the O system, comprise the following steps:

One, gets 100m ³Na ₂SO ₄--NaCl-H ₂O system raw material, wherein component concentration is: NaCl 20g/l, Na ₂SO ₄340g/l evaporates above-mentioned raw materials, and 62 ℃ of vaporization temperatures are carried out solid-liquid separation then and obtained 33.6 tons in sodium sulfate and mother liquid evaporation 6.9m in the raw material ³, the mother liquid evaporation concentration of component is: NaCl 291g/l, Na ₂SO ₄57g/l):

Two, above-mentioned mother liquid evaporation of low-temperature evaporation and circulation system nitre mother liquor and carry out solid-liquid separation and obtain salt-making mother liquor 38.5m ³With 2 tons in sodium-chlor, 50 ℃ of vaporization temperatures, the salt-making mother liquor concentration of component is: NaCl 292g/l, Na ₂SO ₄62g/l;

Three, the above-mentioned salt-making mother liquor of evaporation and carry out solid-liquid separation and obtain making nitre mother liquor 32.2m ³With 0.4 ton in sodium sulfate, 5 ℃ of vaporization temperatures, system nitre mother liquor concentration of component is: NaCl 290g/l, Na ₂SO ₄20g/l, this system nitre mother liquor participates in the low-temperature evaporation salt manufacturing operation in above-mentioned second step of circulation down.

Claims

1, a kind of from Na ₂SO ₄--NaCl-H ₂Produce the technology of sodium sulfate and sodium-chlor in the O system, it is characterized in that it comprises the following steps:

One, gets Na ₂SO ₄--NaCl-H ₂O system raw material, wherein concentration of component is: NaCl 5-320g/l, Na ₂SO ₄5-350g/l evaporates above-mentioned system raw material, and vaporization temperature 60-130 ℃, carry out solid-liquid separation then and obtain sodium sulfate or sodium-chlor and mother liquid evaporation in the raw material, the mother liquid evaporation concentration of component is: NaCl305-290g/l, Na ₂SO ₄50-60g/l;

2, according to claim 1 from Na ₂SO ₄--NaCl-H ₂Produce the technology of sodium sulfate and sodium-chlor in the O system, it is characterized in that Na ₂SO ₄--NaCl-H ₂Contain concentration in the O system for greater than 0 calcium sulfate and/or the sal epsom that is less than or equal to 5g/l.