阅读说明：本技术 一种水泥窑协同处理氯碱盐泥的方法 (Method for cooperatively treating chlor-alkali salt mud in cement kiln ) 是由 尹小林 余智英 宋剑飞 于 2020-07-24 设计创作，主要内容包括：一种水泥窑协同处理氯碱盐泥的方法,包括如下步骤：(1)粒化脱氯盐；(2)水泥窑协同处理。本发明工艺较简单,处理能耗低,处理成本较低,且无二次污染,易于推广应用；有效的脱去氯碱盐泥中的氯盐及汞等重金属,并简单而有效地回收工业盐,获得便于利用的砂粒化脱氯盐泥,防止了氯盐、及易还原挥发的重金属汞等可能造成的二次污染和对窑系统的影响、及对水泥水化性能的影响,并将粒化脱氯脱毒的盐泥固体颗粒,视情或作为活性掺合材、或作为有熟料晶种助烧作用的优质的硅质原料和钙质原料、或替代石膏作调凝剂,清洁化用于水泥窑系统协同处理,利于环境保护和节能减排。(A method for cooperatively treating chlor-alkali salt mud by a cement kiln comprises the following steps: (1) granulating and dechlorinating the salt; (2) and (5) performing synergistic treatment on the cement kiln. The method has the advantages of simple process, low treatment energy consumption, low treatment cost, no secondary pollution and easy popularization and application; the method effectively removes heavy metals such as chloride and mercury in the chlor-alkali salt mud, simply and effectively recovers industrial salt, obtains sand granulation dechlorinated salt mud which is convenient to use, prevents secondary pollution and influence on a kiln system and influence on cement hydration performance which are possibly caused by chloride, heavy metal mercury which is easy to reduce and volatilize and the like, and cleans granulated dechlorinated and detoxified salt mud solid particles as active blending materials or high-quality siliceous raw materials and calcareous raw materials with clinker seed crystal combustion assistance or gypsum substitute as a coagulant, is cleanly used for the cooperative treatment of a cement kiln system, and is beneficial to environmental protection, energy conservation and emission reduction.)

1. The method for the synergistic treatment of chlor-alkali salt mud by the cement kiln is characterized by comprising the following steps:

(1) granulating and dechlorinating salt: placing the chlor-alkali salt mud in a stirring tank, adding a ridger or adding the ridger and introducing kiln tail dedusting smoke under the continuous stirring state, adding water, stirring and mixing for reaction to obtain a granular suspension mixture;

or placing the chlor-alkali salt mud in a stirring tank, adding a strong oxidant or a strong reduction complexing agent, a ridger and/or kiln tail dedusting smoke under the continuous stirring state, adding water, and stirring and mixing for reaction to obtain a granular suspension mixture;

filtering the obtained granular suspension mixture to separate into filtrate and filter residue, washing the filter residue with water, and filtering; collecting the washed filter residues, stacking, air-drying or drying to obtain granulated dechlorinated salt mud;

(2) and (3) cement kiln coprocessing: continuously discharging the granulated dechlorinated salt mud obtained in the step (1) from a kiln head cover of a rotary kiln of a normally-operated dry cement production line into a rotary kiln cooling zone or a grate cooler, and directly converting the granulated dechlorinated salt mud into an active admixture through synergistic heat treatment at the temperature of 1380-800 ℃, wherein the active admixture is mixed in clinker to form mixed clinker;

or the granulated dechlorinated mud obtained in the step (1) is taken as a raw material and sent into a normally operated dry cement production line system from a discharge pipeline at the cone part of a C5 or C6 preheater for cooperative treatment; or crushing the granulated dechlorinated salt mud obtained in the step (1), and sending the crushed dechlorinated salt mud into a dry cement production line system which normally operates from an upper air pipe of a C5 or C6 preheater for cooperative treatment;

or adding the granulated dechlorinated salt mud obtained in the step (1) into raw material ingredients to be used as raw materials for synergistic treatment.

2. The method for co-processing chlor-alkali salty mud in the cement kiln as set forth in claim 1, wherein in the step (1), the chlor-alkali salty mud is carbonate type chlor-alkali salty mud, sulfate type chlor-alkali salty mud or a mixture of more than two of mercury-containing salty mud and non-mercury salty mud.

3. The method for cooperatively treating chlor-alkali salty mud through the cement kiln according to claim 1 or 2, wherein in the step (1), the filtrate is added with a heavy metal ion precipitator, stirred and reacted for 6-60 min, and filtered and separated to obtain heavy metal filter residue and heavy metal-removed filtrate; collecting heavy metal filter residues for additionally extracting valuable substances; adding caustic soda and soda ash into the filtrate for removing heavy metals to react to remove impurities, blowing the residual heat recovered by a cement plant into hot air for boiling drying or negative pressure evaporation drying to obtain industrial-grade sodium chloride for sale, or carrying out melting treatment at 775-1000 ℃ for sale; returning the solid impurities purified by the heavy metal removal filtrate to the chlor-alkali salt sludge to be treated or adding the solid impurities into the granulated dechlorinated salt sludge for application; the condensed water after blast boiling drying or negative pressure evaporation is returned to be used as water for stirring and/or water for cleaning filter residue or is discharged into a waste water pipe network to enter a sewage treatment tank; the heavy metal ion precipitator is at least one of sodium sulfide/potassium, phytic acid and the like, and the amount of the heavy metal ion precipitator is 0.03-3% of the mass of the chlor-alkali salt mud.

4. The method for cooperatively treating chlor-alkali salty mud in a cement kiln according to any one of claims 1 to 3, wherein in the step (1), the solid content is controlled to be 3 to 40% when the water is added for stirring and mixing reaction; the stirring, mixing and reacting time is 30-180 min.

5. The method for cement kiln co-processing chlor-alkali salty mud according to any one of claims 1 to 4, wherein in step (1), said water washing filtrate is returned to be used as water for the agitation mixing reaction.

6. The method for cooperatively treating chlor-alkali salty mud in a cement kiln according to any one of claims 1 to 5, wherein in the step (1), the ridger is at least one of silica fume, activated slag powder, sodium/potassium fluosilicate, sodium/potassium fluoroaluminate, calcium aluminate, calcium sulfoaluminate, calcined alum, clinker powder, cement powder, anhydrite/hemihydrate gypsum powder, and the like, and the ridger is used in an amount of 1 to 50%, preferably 5 to 30%, based on the mass of the chlor-alkali salty mud.

7. The method for co-processing chlor-alkali salty mud in a cement kiln according to any one of claims 1 to 6, wherein in step (1), said strong oxidizing agent is at least one of chlorine dioxide, fluoroantimonic acid, fluorosulfonic acid, ferrate, etc., and the amount of said strong oxidizing agent is 0.1 to 5.0%, preferably 0.3 to 3%, based on the mass of chlor-alkali salty mud.

8. The method for cooperatively treating the chlor-alkali salty mud in the cement kiln according to any one of claims 1 to 7, wherein in the step (1), the strong reducing complexing agent is sodium thiosulfate/potassium, and the amount of the strong reducing complexing agent is 0.5 to 10 percent of the mass of the chlor-alkali salty mud.

9. The method for co-processing chlor-alkali salty mud in a cement kiln according to any one of claims 1 to 8, wherein in the step (1), an alkali displacing agent is added in the stirring and mixing reaction, wherein the alkali displacing agent is at least one of lime and carbide slag; the dosage of the alkali-displacing agent is 1-30% of the mass ratio of the chlor-alkali salt mud, and preferably 3-15%.

10. The method for co-processing chlor-alkali salt mud in a cement kiln as set forth in any one of claims 1 to 9, characterized in that in step (2), said granulated dechlorinated mud is co-processed in an amount corresponding to 0.5 to 50%, preferably 3 to 30%, of the mass of raw meal fed into the kiln system.

Technical Field

The invention relates to a recycling method of chlor-alkali salt mud, in particular to a method for cooperatively treating chlor-alkali salt mud by a cement kiln.

Background

The chlor-alkali salt slurry is a precipitate formed by adding refining agents such as sodium hydroxide, sodium carbonate, ferric trichloride and the like to react with soluble impurities in the refining process of salt water of chlor-alkali enterprises in the ion membrane method alkali production (chlorine, hydrogen and caustic soda are produced by electrolysis), and is discharged from a post-reaction tank through a preprocessor, an HVM membrane filter, and filter press for dewatering, washing with water or air drying. At present, the caustic soda capacity in China is nearly 5000 million t/a, and 50-60 kg of salt mud is generated by domestic devices every 1 t of caustic soda is produced. Due to different raw material sources, different processes or different improvement modes of treatment procedures of the same process, the main mineral components of the salt mud have large difference. The main minerals of the salty mud are roughly classified into sulfate type salty mud (mainly containing calcium sulfate, sodium chloride, etc., which are generally produced in the denitration step by a membrane method) and carbonate type salty mud (mainly containing calcium carbonate, sodium chloride, etc.). According to the mercury content, it can be divided into mercury-containing salt mud and non-mercury salt mud. The salt slurry with different components almost has the common characteristics of mixed components, high salt content, high viscosity and inconvenient utilization of the salt slurry.

At present, sulfate salt mud in chlor-alkali salt mud is relatively easy to separate and dispose. The problem of effective disposal of carbonate mud has always led to the headache of the chlor-alkali industry. The main mineral components of the carbonate mud are calcium carbonate, sodium chloride, magnesium hydroxide, sodium silicate, aluminum hydroxide, ferric hydroxide, a small amount of polyacrylate, cellulose and the like, wherein the content of chloride (NaCl) is generally 5-8%. From the current two kinds of mature and reliable processes of popularization and application in chlor-alkali enterprises, the technical progress of the pall membrane (or kell membrane) process can partially implement the separation and recovery of calcium carbonate, magnesium hydroxide and sodium chloride products from the salt slurry, and the salt slurry mixture produced by the ceramic membrane brine refining process is difficult to effectively separate.

In order to solve the problem of difficult reversion of the environment caused by stacking or landfill of chlor-alkali salt mud, a great deal of research and practice are carried out by technical workers at home and abroad, and the comprehensive utilization of the non-mercury salt mud in the prior art can be roughly summarized as follows:

(1) and (4) preparing the brine drilling fluid by using the brine mud. The application has limitation, application effect or universality is questioned.

(2) Acid treatment is carried out to remove silicate and gypsum, alkalization and gelation are carried out, and then the obtained product reacts with titanate and the like to prepare the porous solid fluorine ion adsorbent for treating fluorine-containing sewage. The method is complex, high in cost, large in secondary pollution and has no advantages in product quality or cost performance.

(3) And adding potassium urea purple into the dried salt mud to prepare the organic fertilizer. Objectively cause pollution diffusion and lead to soil salinization.

(4) The salt mud is used for replacing alkali for sewage treatment. The method is easy to cause secondary pollution and pollution diffusion, and corrode equipment.

(5) The salt mud is dried and mixed with grinding aid components to prepare the auxiliary agents such as early strength grinding aid and the like, and the dried mixed waste residues are used for preparing the cement admixture. The method has certain effect, but the complex minerals in the salt mud affect the durability of the cement concrete application, and the free chlorine causes the corrosion of the reinforcing steel bars.

(6) The small proportion of the salt mud is mixed to fire clay bricks, ceramic particles and ceramic building materials, or mixed to produce autoclaved bricks and the like. The method consumes a small amount of salt mud, and easily causes product deformation or cracking without paying attention.

(7) The salt mud and the carbide slag are rolled and mixed for paving. It is a transfer of pollution and causes erosive migration, and roadbeds are subject to erosion in rainy places.

(8) Separating magnesium hydroxide from salt mud to prepare magnesium oxychloride cement, or drying and adding a large amount of calcined magnesite powder, and mixing to produce magnesium oxychloride cement products such as floor tiles, artificial marble, high-strength inorganic fiber boards, decorative boards and the like. The method has high treatment cost, great secondary pollution and no advantages in product performance.

(9) Drying or roasting, mixing and grinding the powder to prepare the filler for rubber, paper making, plastics and coatings. The method consumes small amount of salt mud, and has no advantages in filler quality or product performance.

(10) The salt slurry can be used as feed additive instead of industrial salt. Objectively, the accumulation and transfer of biotoxicity are easily caused.

(11) The salt slurry dried powder replaces an industrial salt road snow-melting agent. Is objectively a way of transferring and diffusing pollutants.

(12) Separating and recovering calcium carbonate, magnesium hydroxide and sodium chloride. High treatment cost and no economic advantage.

(13) The waste salt slurry of soda ash is used for preparing magnesium carbonate and co-producing calcium carbonate and sodium sulfate. High treatment cost, secondary pollution and no economic advantage.

(14) Mixing 30-35% of quicklime in the salty mud, uniformly drying, then adding 10-15% of hexamethylenetetramine and 10-15% of sodium tetraborate (5-15%), homogenizing, and then crushing to 100-200 meshes to prepare the boiler flue gas desulfurizer. The method causes dirt accumulation and pollution diffusion, and has no advantages in effect and economy.

And (3) treating the mercury-containing salt mud: at present, the technical measures adopted in developed countries are that the method for maintaining the free chlorine content in the fresh brine within the range of 38-42 mg/L in the technical process is used for reducing the precipitation amount of mercury in the refining process, so that the mercury content in the salty mud is lower than 20 mg/kg. The treated mercury-containing salt mud is added with a mercury fixing agent and cement mortar for curing treatment and then buried underground or thrown into deep sea.

The main method for treating the mercury-containing salt mud in China comprises the following steps:

firstly, an oxidation melting method is adopted, namely, sodium hypochlorite is added into mercury-containing salt slurry of saturated brine at the temperature of 50-55 ℃ and under the condition of pH value of 11-12 for reaction for about 50min, so that insoluble mercury is converted into soluble mercury, filtered clear brine is added into a refined brine system, and the filtered clear brine is reduced to metallic mercury on the cathode of an electrolytic cell; the mercury content of the treated salty mud is about 100 mg/kg.

The other is chlorination-sulfurization-roasting method, adding hydrochloric acid into mercury-containing salt mud and introducing chlorine gas to convert the deposited mercury into soluble mercury compound. Adding sodium sulfite to dechlorinate the separated clear liquid, adding sodium sulfide to precipitate mercury ions, separating out precipitate, naturally drying, evaporating most mercury (up to 80%) in a roasting furnace at 800 ℃, and condensing to recover metallic mercury.

Obviously, the method has the obvious problems or defects of small treatment amount, high energy consumption, high secondary pollution, pollution transfer, product quality influence, biotoxicity accumulation, high treatment cost and the like in the non-mercury-containing salt mud or the mercury-containing salt mud, so that a large amount of chlor-alkali salt mud is piled up or discarded or covered with soil, even serious pollution events in the deep desert with disastrous pain are caused, and a method for effectively and synergistically treating the chlor-alkali salt mud by using a cement kiln is further lacked.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects in the prior art and provide a method for cooperatively treating chlor-alkali salt mud by a cement kiln, which can effectively remove most of chlorate and heavy metals in chlor-alkali salt mud, reduce biotoxicity and convert the chlorate and the heavy metals into raw materials for producing cement admixture or clinker.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for cooperatively treating chlor-alkali salt mud by a cement kiln comprises the following steps:

(1) granulating and dechlorinating salt: placing the chlor-alkali salt mud in a stirring tank, adding a ridger or adding the ridger and introducing kiln tail dedusting smoke under the continuous stirring state, adding water, stirring and mixing for reaction to obtain a granular suspension mixture;

or placing the chlor-alkali salt mud in a stirring tank, adding a strong oxidant or a strong reduction complexing agent, a ridger and/or kiln tail dedusting smoke under the continuous stirring state, adding water, and stirring and mixing for reaction to obtain a granular suspension mixture;

filtering the obtained granular suspension mixture to separate into filtrate and filter residue, washing the filter residue with water, and filtering; collecting the washed filter residues, stacking, air-drying or drying to obtain granulated dechlorinated salt mud;

(2) and (3) cement kiln coprocessing: continuously discharging the granulated dechlorinated salt mud obtained in the step (1) from a kiln head cover of a rotary kiln of a normally-operated dry cement production line into a rotary kiln cooling zone or a grate cooler, and directly converting the granulated dechlorinated salt mud into an active admixture through synergistic heat treatment at the temperature of 1380-800 ℃, wherein the active admixture is mixed in clinker to form mixed clinker;

or the granulated dechlorinated mud obtained in the step (1) is taken as a raw material and sent into a normally operated dry cement production line system from a discharge pipeline at the cone part of a C5 or C6 preheater for cooperative treatment; or crushing the granulated dechlorinated salt mud obtained in the step (1), and sending the crushed dechlorinated salt mud into a dry cement production line system which normally operates from an upper air pipe of a C5 or C6 preheater for cooperative treatment;

or adding the granulated dechlorinated salt mud obtained in the step (1) into raw material ingredients to be used as raw materials for synergistic treatment.

Further, in the step (1), the chlor-alkali salt sludge is carbonate type chlor-alkali salt sludge, sulfate type chlor-alkali salt sludge or a mixture of one or more than two of mercury-containing salt sludge and non-mercury salt sludge.

Further, in the step (1), adding a heavy metal ion precipitator into the filtrate, stirring and reacting for 6-60 min, and filtering and separating to obtain heavy metal filter residues and heavy metal removal filtrate; collecting heavy metal filter residues for additionally extracting valuable substances; adding caustic soda and soda ash into the filtrate for removing heavy metals to react to remove impurities, blowing the residual heat recovered by a cement plant into hot air for boiling drying or negative pressure evaporation drying to obtain industrial-grade sodium chloride for sale, or carrying out melting treatment at 775-1000 ℃ for sale; returning the solid impurities purified by the heavy metal removal filtrate to the chlor-alkali salt sludge to be treated or adding the solid impurities into the granulated dechlorinated salt sludge for application; the condensed water after blast boiling drying or negative pressure evaporation is returned to be used as water for stirring and/or water for cleaning filter residue or is discharged into a waste water pipe network to enter a sewage treatment tank; the heavy metal ion precipitator is at least one of sodium sulfide/potassium, phytic acid and the like, and the amount of the heavy metal ion precipitator is 0.03-3% of the mass of the chlor-alkali salt mud.

Further, in the step (1), the solid content is controlled to be 3-40% when the water is added for stirring and mixing reaction; the stirring, mixing and reacting time is 30-180 min, preferably 60-100 min.

Further, in the step (1), the water-washed filtrate is returned to be used as water for stirring and mixing the reaction.

Further, in the step (1), the ridger is at least one of silicon powder, silica fume powder, active slag powder, sodium/potassium fluosilicate, sodium/potassium fluoaluminate, calcium aluminate, calcium sulfoaluminate, calcined alum, clinker powder, cement powder, anhydrite/semi-hydrated gypsum powder and the like, and the dosage of the ridger is 1-50% of the mass of the chlor-alkali salt slurry, preferably 5-30%. Adding a ridge agent to react and solidify minerals such as silicon, aluminum, iron, calcium, magnesium and the like in the chlor-alkali salt mud to form a granular suspension mixture which is easy to dehydrate; the mixed material can be carbonized by introducing the dust-removing flue gas at the tail of the kiln.

Further, in the step (1), the strong oxidant is at least one of chlorine dioxide, fluorine antimonic acid, fluorine sulfonic acid, ferrate and the like, and the dosage of the strong oxidant is 0.1-5.0%, preferably 0.3-3% of the mass of the chlor-alkali salt mud.

Further, in the step (1), the strong reduction complexing agent is sodium thiosulfate/potassium, and the using amount of the strong reduction complexing agent is 0.5-10% of the mass of the chlor-alkali salt slurry.

The addition of the strong oxidant or the strong reduction complexing agent can oxidize or strongly reduce the volatile heavy metal particles such as mercury in the chlor-alkali salt mud to be converted into heavy metal ions to enter the solution, and promote the minerals such as silicon, aluminum, iron, calcium, magnesium and the like in the chlor-alkali salt mud to react and solidify to form a granular suspension mixture which is easy to dehydrate.

Further, in the step (1), an alkali replacement agent can be added in the stirring and mixing reaction, wherein the alkali replacement agent is at least one of lime and carbide slag; the dosage of the alkali-displacing agent is 1-30% of the mass ratio of the chlor-alkali salt mud, and preferably 3-15%. The addition of the alkali replacement agent can replace potassium and sodium ions in the chlor-alkali salt mud mixed mineral by calcium ions, and the potassium and sodium ions are recycled, so that the output value is improved.

Further, in the step (2), the synergistic treatment amount of the granulated dechlorinated salt mud is 0.5-50%, preferably 5-30% of the mass of the raw material powder fed into the kiln system.

When the granulated dechlorinated salt mud obtained in the step (1) is subjected to synergistic treatment in a cement kiln after the sulfate type chlor-alkali salt mud is granulated and dechlorinated, the granulated dechlorinated salt mud can be used as a coagulation regulator for cement production instead of gypsum.

When the granulated dechlorinated salt mud is taken as a blending material to enter a cement kiln for synergistic treatment, the granulated material which is continuously discharged into a kiln hood (containing a rotary kiln internal cooling pressure-rising belt) in an alkaline dust environment is rapidly roasted in an oxidizing atmosphere at 1380-900 ℃, a small amount of organic combustible substances contained in the granulated material particles are rapidly burnt out, inorganic minerals in the granulated material particles are thermally activated and dehydrated into active silicate minerals or thermally decomposed into oxides with potential hydraulic activity and partially react to generate active aluminosilicate minerals, residual trace heavy metal ions are high-activity aluminosilicate groups and are firmly melted, and residual chlorine and sulfur are combined with new high-activity CaO in the oxidizing atmosphere to be converted into calcium chloride, the calcium sulfate participates in the reaction of calcium chloroaluminate and calcium sulfoaluminate (the calcium chloroaluminate mineral does not corrode a steel bar), and the residual alkali metal ions are combined with high-activity aluminosilicate groups to form the aluminosilicate mineral.

The sand grain dechlorinated salt mud is taken as a raw material to enter a cement kiln for cooperative treatment, the sand grain dechlorinated salt mud is sent into a dry cement production line system which normally operates from a discharge pipeline at the cone part of a C5 (five-level preheater) or a C6 (six-level preheater) preheater which contains a large amount of high-temperature calcium oxide powder to be cooperatively treated, cold sand grain dechlorinated salt mud fed from a discharge chute at the cone part of a C5 or C6 cyclone preheater is flushed into a kiln tail smoke chamber along with hot material powder containing a large amount of high-temperature calcium oxide powder to enter a rotary kiln for oxidizing atmosphere calcination, sand grain dechlorinated salt mud particles which are wrapped by strong-base high-temperature powder are quickly alkalized and dehydrated at high temperature to 800-1050 ℃, the reduction volatilization of a small amount of residual heavy metal and chlor-alkali sulfur is inhibited, inorganic minerals in the sand grain dechlorinated salt mud particles or silicate mineral seeds which are dehydrated to have the combustion assisting effect or are thermally decomposed into active oxides, the residual trace heavy metal ions are trapped and melted by the high-activity aluminosilicate radical, the residual chlorine and sulfur are combined with the new high-activity CaO in the non-reducing atmosphere in the rotary kiln to be converted into calcium chloride and calcium sulfate to participate in the calcium chloroaluminate and calcium sulfoaluminate reaction (the calcium chloroaluminate mineral does not corrode a steel bar), and the residual alkali metal ions are combined with the high-activity aluminosilicate radical to form the aluminosilicate mineral.

The sand-granulated dechlorinated salt mud is taken as a raw material and enters a cement kiln for cooperative treatment, and the crushed sand-granulated dechlorinated salt mud is fed from an upstream air duct of a C5 cyclone preheater. The hot air flow rich in high-temperature calcium oxide micro powder and the hot raw material powder are quickly preheated and mixed by a C4 cyclone preheater to form mixed raw material powder, the mixed raw material powder is discharged into a decomposing furnace (the time consumption is about 8 seconds) and is suspended and smokeless to burn along with pulling wind, namely, the modified sand-granulated dechlorinated mud is quickly heated to 680-800 ℃ from the normal temperature cold state in the environment of alkaline powder in an ascending air pipe of an anoxic C5 cyclone preheater and a C4 cyclone preheater, the temperature rapidly exceeds a volatilization cracking reduction temperature section, the reduction volatilization of residual heavy metal and chlor-alkali sulfur is inhibited, the quick heating only obtains and removes free water and combined water in the sand-granulated dechlorinated mud, the inorganic mineral or the dehydrated and activated clinker seed crystal mineral in the sand-granulated dechlorinated mud particles suspended in the decomposing furnace along with the pulling wind, or the inorganic mineral or the thermally decomposed into active oxide which is all components of raw material components, the residual trace heavy metal ions are trapped and melted by the high-activity aluminosilicate radical, the residual chlorine and sulfur are combined and converted into calcium chloride and calcium sulfate with the new high-activity CaO in the non-reducing atmosphere in the decomposing furnace to participate in the reaction of calcium chloroaluminate and calcium sulfoaluminate, and the alkali metal ions are combined with the high-activity aluminosilicate radical.

The invention has the following beneficial effects: 1) the method is simple, the investment is less, the treatment energy consumption is low, the treatment cost is lower, no secondary pollution is caused, and the popularization and the application are easy; 2) Aiming at the characteristics of mature dry cement production line process equipment and the requirements of cement production on a silicon-aluminum raw material, a calcium raw material and a retarder, a ridger/kiln tail dedusting flue gas oxidant or a strong reduction complexing agent and the like are added with water for stirring and mixing reaction, minerals such as silicon-aluminum-iron-calcium-magnesium and the like in chlor-alkali salt mud are reacted and solidified to form a granular mixture which is easy to dehydrate and purify, heavy metals such as chloride salt, mercury and the like in chlor-alkali salt mud are effectively removed, industrial salt is simply and effectively recovered, sand-granulated dechlorinated salt mud which is convenient to use is obtained, secondary pollution and the influence on a kiln system and the influence on cement hydration performance which are possibly caused by chloride salt, heavy metal mercury which is easy to reduce and volatilize are prevented, and sand-granulated and dechlorinated salt mud solid particles are used as an active blending material or a high-quality siliceous raw material and a calcium raw material which have a clinker crystal seed combustion assisting effect, Or replace gypsum as a coagulation regulator, is cleanly used for the cooperative treatment of a cement kiln system, and is beneficial to environmental protection, energy conservation and emission reduction.

Detailed Description

The present invention will be further described with reference to the following examples.

The chemical reagents used in the examples of the present invention, unless otherwise specified, are commercially available in a conventional manner.

The following examples of the present invention relate to criteria including: DB 37/T1939-2011 is used for solid wastes in cement production, GB 18597-2001 standard for controlling pollution of storage of dangerous wastes, Standard Corrosion differentiation of dangerous wastes (GB 5085.1-2007), Standard Leaching toxicity differentiation of dangerous wastes (GB 5085.3-2007), Standard general rules of identification of dangerous wastes (GB 5085.7), Standard content differentiation of toxic substances of hazardous wastes (GB 5085.6), Standard reactivity differentiation of hazardous wastes (GB 5085.5), Standard Specification of identification of hazardous wastes (HJ/T298), and TCLP experiment detection of clinker by using a toxicity characteristic Leaching method.

The following embodiments are all carried out on a phi 4 x 60m cement production line with a five-stage cyclone preheater predecomposition kiln drying method of a certain enterprise, the stability of the normal production kiln condition is general, the fluctuation of the clinker strength is 24.6-32.4 MPa in 3d compressive strength and 52.8-57.6 MPa in 28d compressive strength, the fluctuation of the water requirement of the standard consistency is 22.5-27.5%, the fluctuation of the setting time is 104-137 min in initial setting and 139-168 min in final setting, and the clinker chloride ion (Cl)^-) The content is 0.013%.