CN103510151B - Method for preparing calcium sulfate whiskers from dolomite - Google Patents
Method for preparing calcium sulfate whiskers from dolomite Download PDFInfo
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- CN103510151B CN103510151B CN201310405237.3A CN201310405237A CN103510151B CN 103510151 B CN103510151 B CN 103510151B CN 201310405237 A CN201310405237 A CN 201310405237A CN 103510151 B CN103510151 B CN 103510151B
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Abstract
The invention relates to a method for preparing calcium sulfate whiskers from dolomite. The method comprises the process steps that: dolomite is grinded into mineral powder, and is placed into a leaching container; hydrochloric acid is added, such that a chloride mixed solution is prepared; lime cream is added, such that a CaCl2 solution is obtained; the CaCl2 solution is placed into a pressure container; a crystal modifier is added, and sulfuric acid is added; the mixture is sufficiently stirred; the temperature and the pressure are maintained, such that calcium sulfate hemihydrate whisker floc is prepared; the floc solution is processed through hot filtration and hot-water-washing filtration, such that high-quality calcium sulfate hemihydrate whiskers are obtained; the calcium sulfate hemihydrate whiskers are dried under a temperature of 170-180 DEG C, such that anhydrous calcium sulfate whiskers are obtained. The anhydrous calcium sulfate whiskers provided by the invention has the advantages of high orderliness, complete crystal, and high strength. The method has the advantages of simple operation, high whisker yield, and high economic benefit.
Description
Technical field the present invention relates to a kind of production technique of whisker, relate in particular to a kind of by dolomite made the production technique for calcium sulfate crystal whiskers.
Background technology China is one, and Mineral resources kind is more complete but country that resource is not abundant is also a country that average resource per capita is very low, consumption is large.China is that the country that global mineral wealth exploitation total amount is very large (mainly focuses on development of metallic mineral and energy source mineral at present, other non-metallic minerals development ratios are quite little), but the gross national product that we create with this and industrially developed country can mention in the same breath hardly.Trace it to its cause: be exactly because our mineral products processing is with low content of technology, price is low, benefit is low.Therefore, develop the height appreciation deep processing and utilization of mineral products, represented the developing direction of advanced productivity, meet the requirement of the Scientific Outlook on Development.Non-metallic minerals takes up an area 95% of ball mineral wealth total amount, in the world, whether the ratio of the non-metallic minerals output value and the metalliferous mineral output value is greater than 1, be a judgement criteria weighing a national Industry Development Level, be one of whether ripe important symbol of the national technical progress of measurement and industrialization always.China is that a nonmetal resource is relatively abundant, but the very underdeveloped country of nonmetal industry, the height of conscientiously studying nonmetal resource appreciates and is optimized utilization, particularly important for the country in our fast development.In recent years, country has put into effect the policy document of much developing, utilizing about nonmetal mineral resource in succession, and the development of nonmetal industry is extremely urgent, very urgent.
Whisker refer to there is fixing shape of cross section, complete profile, perfect internal structure, length-to-diameter ratio be up to 5-1000 fibrous single crystal.Because whisker is monocrystalline, so have very high intensity, its intensity, close to the theoretical strength of valence link between material atom, is extraordinary reinforcing component.Since eleutheromorph beard and hair is existing, every country material scholars attach great importance to, and the whisker of having developed at present has inorganic crystal whisker (metal, oxide compound, carbide, nitride, inorganic salts, graphite etc.) and organic crystalline palpus (polymer class etc.).Toughness reinforcing metal matrix, the ceramic matric composite of inorganic crystal whisker Material reinforcement has been widely applied to the fields such as machinery, electronics, chemical industry, national defence, the energy, environmental protection, as can be seen here, inorganic crystal whisker is to the upgrading of product and increase economic efficiency, have great promoter action, the synthetic and application in material of whisker will become one of focus of Materials science.Whisker, as of paramount importance enhancing part in matrix material, has obtained the great attention of industrially developed country.From the eighties in 20th century, China's emphasis is studied whiskers such as carbon fiber, silicon carbide, aluminum oxide, silicon nitrides, these whisker excellent performances, but expensive, can only be for some special industry.And compare with these whiskers, calcium sulfate crystal whiskers, as a kind of inorganic crystal whisker, has following characteristics: cost is low, and its cost is only equivalent to silicon carbide whisker
1/ 200 to
1/ 300; High temperature resistant, anhydrous calcium sulfate whisker heats only weightless 0.75% (anhydrous calcium sulfate whisker fusing point is 1450 ℃) of 2h at 1800 ℃, and asbestos weightlessness 13.77% under similarity condition; Resistance to acids and bases is good, and resist chemical, good toughness, electrical insulating property is good, intensity is high, easily carry out surface treatment, also possesses good intermiscibility and smoothness and the advantage such as nontoxic simultaneously.Calcium sulfate crystal whiskers is because of its high performance-price ratio and the huge applications prospect in matrix material, and become the focus of Material Field research, calcium sulfate crystal whiskers can be used for toughener or the functional type filler in polyurethane, rubber, coating, papermaking completely, can be used for again friction materials, material of construction, insulation and fire retardant material etc., production cost is low is incomparable in all whisker kinds, because of calcium sulfate crystal whiskers nontoxic, to human body without harm, it is a kind of green novel environment friendly material, the huge market demand, development prospect is good.
Calcium sulfate crystal whiskers (claiming again crystal whisker of gypsum) refers to the fibrous single crystal of calcium sulfate, it have three kinds of terra alba, calcium sulphate hemihydrate and anhydrous calcium sulfate whiskers minute.When but Dihydrate gypsum whiskers and hemihydrate calcium sulfate crystal whisker are used higher than 110 ℃ and 160 ℃ respectively in temperature, all can dewater efflorescence and destroy, not have the enhancement of whisker, prospects for commercial application is little; And anhydrous calcium sulfate whisker still can keep good state at 680 ℃, there is higher intensity and use value, prospects for commercial application is extensive.
The technology of preparing of domestic current existing calcium sulfate crystal whiskers is that to take gypsum (gypsum raw material is plaster of paris mineral and industry by-product gypsum normally) be raw material, and preparation method can roughly be divided into three kinds: the hot method of hydraulic pressure, normal pressure acidization and the by-product calcium sulfate crystal whiskers of direct output when producing phosphoric acid and citric acid.The hot method of hydraulic pressure and normal pressure acidization (this two method is similar) are all in the aqueous solution, by solid CaSO
42H
2o powder, under certain temperature or certain pressure, by means of crystal formation changing agent, makes α gypsum towards fibrous crystallization, and technical process is generally: grinding → material → hydro-thermal reaction → solid-liquid separation → surface treatment with slurry → dry → product.
Traditional method of preparing anhydrous calcium sulfate whisker with plaster stone or industrial by-product dihydrate gypsum, essence is a solid CaSO
42H
2o dissolves, CaSO
41/2H
2o crystallisation process, its chemical equation is as follows:
plaster stone belongs to oblique system, Ca
2+connect SO
4 2-tetrahedron has formed laminate structure, H
2o molecule is distributed between bilayer, Ca
2+ligancy be 8, except with belong to adjacent four SO
4 2-in 6 O
2-outside interconnecting, also with 2 H
2o molecule is connected.Plaster stone generally have be parallel to [010] face platy morphology and can dissociate completely along this face.Calcium sulfate crystal whiskers is oblique system, on [100] and [010] face, and Ca
2+connect SO
4 2-tetrahedral has become laminate structure, can layering on [001] face, and Ca
2+and SO
4 2-in coaxial direction, connect into chain, therefore calcium sulfate crystal whiskers is and is parallel to coaxial fibrously, interchain exists the passage of " narrow and small ", in this passage, holds crystal water.Ca
2+ligancy be 6, with four adjacent SO
4 2-in 6 O
2-be connected, crystal water is just connected to SO by hydrogen bond
4 2-on.
The chemical formula of rhombspar is CaMg (CO
3)
2(or xCaCO
3yMgCO
3), in natural rhombspar mineral, the content of CaO and MgO can approach respectively 30% and 20% left and right, and in rhombspar mineral, common impurity element has Fe, Mn, Al, Zn, Pb, Si etc.Rhombspar mineral are white in color, grey, and iron content is many is brown, vitreous luster, and fracture is stepped, flat condition sometimes, property is crisp, hardness 3.5-4, relative density 2.87, capacity antacid is poor, is soluble in acid and emits CO
2gas.Rhombspar is widely distributed rock forming mineral, in China various places, extensively distributes, and reserves are huge.As mining area, Heng Wo ridge, Ningyuan County, Hunan Province, Guyang District, inner Mongolia county, Nanjing Technology in Mine Spoils in Mufu Mountain, Shuicheng city etc.
Current existing calcium sulfate crystal whiskers technology of preparing is that to take the plaster of paris or industry by-product gypsum be raw material, belongs to Mineral Transformation method.It is (as variable at random in the existence of different impurity that purity, whiteness, fibre content and other all technicals of the calcium sulfate crystal whiskers that the method is produced can be subject to the variation of raw mineral materials purity and impurity composition, and content is separately difficult for stable existence in narrow scope), the difficulty thereby the controllability that makes whisker growth becomes, as the random appearance of in raw material, whisker growth being poisoned to thing can make the difficult control that causes confusion of whisker building-up process, cause quality product to be difficult for reaching its ideal effect.
Summary of the invention the technical problem to be solved in the present invention is to provide a kind ofly take rhombspar and prepares the method for the anhydrous calcium sulfate whisker of high purity, high whiteness, big L/D ratio as raw material.
Technical scheme of the present invention comprises following processing step:
(1) by rhombspar raw ore through Mechanical Crushing ore grinding, breeze is after Weighing, immigration is soaked in the container of ore deposit, the acid solution (this hydrochloric acid can be the HCl regenerated liquid after output hemihydrate calcium sulfate crystal whisker) that adds metering salt, in rhombspar raw ore CaO, MgO content be respectively 29.8%, 19.75%, concentration of hydrochloric acid solution best results while being 8%, under whipped state question response basic completely after, insert the medicines such as appropriate neutralization, removal of impurities, through sizing mixing, sink the removal of impurity, filtering gained ore leachate is purer Ca
2+, Mg
2+muriate mixing solutions; Soak the CO producing in the reaction process of ore deposit
2gas, processes (because of the CO reclaiming through appropriate depickling removal of impurities
2in gas, contain a small amount of foreign gases such as acid mist), for producing dry ice product;
Reaction equation: MgCO
3caCO
3+ 4HCl → MgCl
2,+CaCl
2+ 2CO
2↑+2H
2o (carrying out in closed container)
(2) by Ca
2+, Mg
2+mixed chloride leach liquor, move into de-Mg
2+in container, add the lime emulsion of metering, take off Mg
2+reaction, lime emulsion is lime emulsion the best of moisture 40%, the filtrate of gained is containing Ca after filtering
2+concentration is higher compared with stoste, impurity CaCl still less
2solution, the Mg in leach liquor
2+the precipitated Mg (OH) that is
2separate out (this crude product Mg (OH)
2the raw material of producing high purity light activated magnesia or magnesium salt whisker);
Chemical equation: MgCl
2+ Ca (OH)
2→ Mg (OH)
2↓+CaCl
2
2FeCl
3(AlCl
3deng)+3Ca (OH)
2→ 2Fe (OH)
3[Al (OH)
3deng] ↓+3CaCl
2
(3) by Ca
2+, Mg
2+the Ca of gained after separated
2+solution adds the powerful cleaner degree of depth to remove after the nuisance of inhibition of whiskers growth again, in filtering the settled solution of gained, add appropriate gas chromatography crystal modifier to do short brilliant matchmaker, growth substance (that these medicaments play respectively in growth whisker process is modified, change phase, turn the effects such as crystalline substance, growth, dispersion) and the vitriol oil, sulfuric acid concentration is vitriol oil the best of 98%, in the pressurized vessel of temperature rating, pressure after throwing liquid and completing, through heat-insulation pressure keeping 30 minutes, make hemihydrate calcium sulfate crystal whisker
● according to test gained process data, show, as done under adjusting material condition at concentration 8%HCI, 110-120 ℃ of temperature and interpolation organism etc., the CaSO under this hot acid effect
4meltage is about 3-5%, is greater than remaining CaSO after this meltage
4be CaSO
41/2H
2o whisker is separated out;
Through de-Mg
2+after rich Ca
2+solution, containing Ca
2+ionic concn is about 54g/L left and right, through adding H metering, that concentration is specified
2sO
4after, can separate out mass concentration in unit volume and be greater than the anhydrous CaSO of 150g/L
4whisker drying products (productive rate of product is greater than 15%);
(4) will generate after the pressurized vessel release of cotton-shaped material (being hemihydrate calcium sulfate crystal whisker) of fiber (whisker), be with immediately heat filtering, hot wash, filtration minute completes for four times: first, under the environment of temperature>=90 ℃, filter, filter containing the hemihydrate calcium sulfate crystal whisker of raffinate; The second, by filtering containing the fully washing and filtering in the hot water of temperature>=90 ℃ of the hemihydrate calcium sulfate crystal whisker of raffinate, obtain pure hemihydrate calcium sulfate crystal whisker; The 3rd, the hemihydrate calcium sulfate crystal whisker of filtering purely, again by modification in the hot water of temperature>=90 ℃, washing and filtration, is obtained to the hemihydrate calcium sulfate crystal whisker after modification, filtrate is returned to second segment for hot wash and filtration; The 4th, the filtrate of gained after first paragraph and second segment filtration is merged to immigration container for storing liquid, after naturally cooling, separate out Dihydrate gypsum whiskers, after filter, Dihydrate gypsum whiskers is turned back in the pressurized vessel of making hemihydrate calcium sulfate crystal whisker and used as crystal seed, and gained filtrate is regeneration of hydrochloric acid liquid, and its main component is hydrochloric acid and remaining Ca
2+mixed acid solution, returning to circulation and soaking dolomite mineral;
(5) dry by being placed at 170 1 180 ℃ of temperature through the hemihydrate calcium sulfate crystal whisker of modification after washing and filtering, dry 3.5 hours, make anhydrous calcium sulfate whisker (the anhydrous calcium sulfate whisker product after modification adopts and packs),
Adopt the beneficial effect of technical solution of the present invention:
(1) this technique anhydrous calcium sulfate whisker is by monocrystalline form growth mechanism preparation, and whisker is that order is high, crystal perfection, whisker that diameter≤2um intensity is high.The single crystal of this delicacy, internal structure is very complete, has very tough and tensile character.There is high breaking tenacity and Young's modulus, if its tensile strength is 5-10 times of glass fibre.And it does not have obvious fatigue characteristic, even if be ground into powder, fracture, its intensity can not suffered a loss yet, and makes the matrix material that contains calcium sulfate crystal whiskers have reusability, and material also changes not quite through repeatedly processing mechanical property, and regeneration use properties is fine.So having good application prospect aspect matrix material, water treatment, road modified asphalt, coating, paint, fire-retardant fireproof material, papermaking.
(2) this process characteristic is: simple to operate, production whole process is operation under the controlled recurrent state of material balance, and spent acid, waste water, waste residue (be rich in gypsum composition, send cement mill) reach zero release substantially; Raw material cheapness (the main raw material: rhombspar, dense H that is easy to get
2sO
4); Soaking mining acid can recycle; Hemihydrate calcium sulfate crystal whisker is synthetic in full liquid phase; Calcium sulfate crystal whiskers output capacity high (>=15%) in unit volume; The byproduct added value economic benefit high, its output value of deep processing is not less than the economic benefit of major product.The energy-saving technique that belongs to circulation, high-quality, high yield, the anhydrous calcium sulfate whisker whiteness of production, purity, Whisker Content all reach more than 97%, and length-to-diameter ratio reaches 30-300.
(3) byproduct has dry ice and magnesium salt whisker or magnesium hydroxide, lightweight activated magnesia etc.
Description of drawings 1 is that the present invention prepares anhydrous calcium sulfate whisker process flow diagram;
Fig. 2 is the electron microscope picture of product anhydrous calcium sulfate whisker of the present invention.
Embodiment describes the present invention in detail below in conjunction with accompanying drawing, and technical scheme of the present invention comprises following processing step:
(1) grinding, soak ore deposit: take rhombspar as raw material, with mechanical ore grindings such as jaw crusher, ball mills, gained rhombspar breeze, rhombspar breeze is used to regeneration of hydrochloric acid immersion ore deposit, in rhombspar raw ore CaO, MgO content be respectively 29.8%, 19.75%, concentration of hydrochloric acid solution best results while being 8%, after abundant stirring reaction is complete, by removal of impurities, filtration, make Ca
2+, Mg
2+muriate mixing solutions, meanwhile, the CO of output in this process
2gas can make dry ice byproduct by remove acid mist, purification, be dried etc. again;
(2) de-Mg
2+, filter: Ca
2+, Mg
2+muriate mixing solutions, adds the lime emulsion of metering to make Ca
2+, Mg
2+separation, lime emulsion is lime emulsion the best of moisture 40%, gained filtrate is the pure CaCl of concentrate after filtration
2solution, for calcium sulfate crystal whiskers processed, the separating obtained Mg (OH) that is rich in
2filter residue is for the production of the active high-purity MgO of lightweight and magnesium salt whisker;
(3) steam pressure, crystallization: by CaCl
2solution is placed in 110 ℃, the pressurized vessel of about 0.2MPa, inserts crystal modifier simultaneously, then adds the appropriate vitriol oil, sulfuric acid concentration is vitriol oil the best of 98%, fully stirs, and speed control is 80 revs/min of the bests, through insulation, pressurize 30 minutes, can make hemihydrate calcium sulfate crystal whisker floss;
(4) modification, heat filter: after pressurized vessel release, hemihydrate calcium sulfate crystal whisker floss solution is passed through to band heat filtering and hot wash, water temperature is controlled at>=and 90 ℃, filtration can obtain pure, dispersed good hemihydrate calcium sulfate crystal whisker, through modified stable, process and move into drying operation, hot filtrate moves into container for storing liquid, and naturally cooling is separated out CaSO
42H
2o fiber, CaSO after filter
42H
2in O fiber returning pressure container, make crystal seed and use, filtrate returning soaked ore deposit and recycled;
(5) dry, finished product: heat is filtered to stable hemihydrate calcium sulfate crystal whisker after modification and be placed under the condition of 170-180 ℃ and be dried, be 3.5 hours time of drying, makes finished product sulfuric acid calcium pyroborate.
Main material consumption and byproduct:
1 ton of calcium sulfate crystal whiskers of every production: need rhombspar (being respectively 29.8% and 19.75% containing CaO, MgO) to be approximately greater than 0.7198 ton; Need 31% 1.82 tons of hydrochloric acid (transformation efficiency is about 95%), wherein the wastage rate of hydrochloric acid are approximately greater than 5%, 0.091 ton of consumption, 1.729 tons of the hydrochloric acid (by 31% concentration conversion) of recoverable; Need 98% 0.77 ton of the vitriol oil (transformation efficiency is in 95% left and right); Need 0.21 ton of unslaked lime CaO (transformation efficiency is 93%).
1 ton of calcium sulfate crystal whiskers of every production can by-product: CO
2about 0.275 ton of dry ice (only having 85% utilization ratio), can by-product Mg (OH)
2about 0.21 ton (approaching 93% transformation efficiency).
The main technique equipment of production line of the present invention has: ball mill, pulping device, dosing unit, measuring apparatus, container for storing liquid, stirring, filtering system, volume pump, enamel glass cylinder of steel (pressurized vessel), drying machine, rotary conveyor, wrapping machine, steam boiler, heat-conducting oil furnace, waste-heat recovery device, fly-ash separator and power supply, water supply, automatization control and laboratory configuration Controlling System etc.
Prepared anhydrous calcium sulfate whisker is got the production sample of a plurality of batches, and as shown in Figure 2, gained physico-chemical analysis project and result are: composition: CaSO
4; Purity>=98%; Whiteness>=97%; Whisker Content>=98%; Diameter: 0.64～1.79um; Length: 50～300um; Length-to-diameter ratio: 30～300; Fusing point: 1450 ℃; Refractive index 1.585; Water-soluble (22 ℃) <2g/L; Relative density 2.69g/cm3; Loose capacity: 0.15～0.25g/cm3; Tensile strength: 20.3-20.5GPa; Tensile modulus 176-179GPa; Mohs' hardness: 3.4-4; PH value: 6～8.
The production that the 100 tons of rhombspar raw ores of (24 hours) processing of take below continuous every day synthesize anhydrous calcium sulfate whisker is example, describes production process in detail:
(1) grinding ore operation: the rhombspar raw ore of a large amount of exploitations in mine, through dry rhombspar breeze broken, ball mill dry grinding, put into raw material warehouse, in comprehensive sample examination raw material, CaO, MgO content are respectively 29.8%, 19.75% (different section CaO, MgO content are understood variable in ore body);
(2) rhombspar breeze dissolves and leaches operation:
Soaking ore deposit container is 50m
36 of the closed tins of volume, conspire to create one group by 3, and minute two groups and use are first soaked ore deposit tank by one group 3 wherein and injected respectively 31m
3concentration is that 86.57g/L regenerant salt leaching-ore liquid (contains CaCl in solution
221.74g/L), the rhombspar breeze of dry grinding is through conveyor feed, deliver in the weighing hopper that soaks tank top, ore deposit, before breeze feeds intake, first the circulation stirring pump that soaks ore deposit tank is opened, tank body top solution is extracted into bottom to pump, pump go out liquid material spray tube mouth and tank body is cut sth. askew, and it is fixed on to commissioning pipe bottom (accept the degree of depth that the commissioning pipe of breeze inserts in tank body solution and be generally 1 meter of left and right), until immersion liquid in tank, after being stirred rolling normally, started slowly continuously the rhombspar breeze of nearly 4.2 tons/tank metering to be put into each airtight soaking in the tank of ore deposit through feed straight tube, in tank, start output CO
2after gas, with blind enema (CO
2proportion large compared with air), the air in tank body is got rid of through a high position emptying (dirt) valve, detect CO simultaneously
2gas purity, CO to be recorded
2after gas purity is qualified, emptying (dirt) valve cuts out to the CO of generation
2gas removes after refining plant purification by acid mist, steam etc., send dry ice Workshop Production dry ice product,
Along with carrying out continuously of feeding intake, the CO of output
2gas is that intensive slurry bubble shape is surging to be overflowed in high-order froth breaker, after circulated sprinkling froth breaking, liquid phase part meeting nature flow back into 3 airtight soaking in the slack tank of ore deposit of another group, and in time hydrops is pumped back to respectively to just soaking in the tank of ore deposit in operation, approximately through reaction in 2 hours, substantially complete, to each, soak ore deposit tank respectively and add appropriate milk of lime to size mixing, and only survey pH value>=8 with pH value test paper.This organizes the about 95m of 3 tank
3acid solution soak ore deposit operation and complete, another is organized 3 tanks and starts the same operation continuously.So hocket, by every 3 tanks, it is one batch, every batch completes for 3 hours, 24 hours through 8 subjobs, the molten ore deposit of soaking of rhombspar breeze acid 100 tons/every day can be completed to (it is excessive that rhombspar breeze requires in leaching operation, object is to improve or increase the water-permeable of slag while filtering, and makes filter residue and filtrate separated and washing rapidly when filtering).Through centrifugal and secondary filter, can obtain successively the about 760m of cumulative volume
3caCl
2, MgCl
2mix infusion solution;
Rhombspar is solubilizing reaction equation in hydrochloric acid: CaMg (CO
3)
2+ 4HCl---→ CaCl
2+ MgCl
2+ 2CO
2↑+2H
2o
(3) Ca
2+, Mg
2+the de-Mg of mixed chloride
2+flow chart:
The ore leachate obtaining successively from above-mentioned operation, through sample examination CaCl
2, MgCl
2evenly content is respectively 88.82g/L, 55.77g/L, every 3 hours, has 95M
3left and right is containing MgCl
2the rhombspar ore leachate of 52.26-59.28g/L flows to de-Mg
2+operation section, 95M
3treat de-Mg
2+liquid, moves into volume 100M
3de-Mg
2+in groove, at de-Mg
2+in the sieve bucket of groove, put into successively the lime emulsion of 7.38 tons moisture 40%, under water blast gun (note) impacts, till joining successively lime emulsion in sieve bucket all the punching of the circulation suspension liquid in groove being filtered dry only.Then with pump, whole groove material is moved in the aging tank of band stirring to ageing Mg (OH)
2, treat the Mg in aging tank
2+transformation efficiency in solution 93% left and right and thoroughly the positively charged ion that can transmit precipitation of hydroxide is heavy remove after, send plate-and-frame filter press to filter, filter cake is crude product Mg (OH)
2(being the raw material of MgO and magnesium salt whisker deep processing), obtains about 95M
3mgCl in filter liquor
2content is down to 3.79g/L by original 55.77g/L, CaCl
2concentration is increased to 144.91g/L by original 88.82g/L;
With 95M
3liquid material is → individual lot-to-lot, every batch of de-Mg
2+operation completed in 3 hours.The de-Mg of 100 tons of rhombspar raw ore gained of every processing
2+the volume of filtrate can be by 760m
3be increased to 782.7M
3, reason is the Ca (OH) from 59.04 tons moisture 40%
2in lime emulsion, add 22.7M
3cause;
CaCl
2, MgCl
2de-Mg in solution
2+equation: MgCl
2+ Ca (OH)
2→ → Mg (OH)
2↓+CaCl
2
Removal of impurities reaction equation: 2FeCl
3(A1Cl
3deng)+3Ca (OH)
2→ 2Fe (OH)
3[Al (OH)
3deng] ↓+3CaCl
2
(4) the deep impurity-removing operation of thing is poisoned in inhibition of whiskers growth;
(5) CaSO in water
41/2H
2o whisker synthesis procedure:
CaCl
2preheating of solution: the CaCl of clarification
2solution, proceeds in heat exchange groove (with boiler exhaust gas or damp and hot tail gas when dry, the wherein damp and hot tail gas of dehumidification system, the recyclable bath water of doing of water of condensation after heat exchange cooling), through the heat exchange of stainless steel heat exchange pipe, when indirect heating arrives 70-80 ℃, continued next procedure;
30M
3every 5 of enamel reaction still is one group, and minute two groups of replacement are carried out, and first the feeding intake of each enamel reaction still of a group is wherein covered and emptying vent valve is opened.Respectively add about 700Kg left and right containing the CaSO of total moisture 35%
42H
2o fiber crystal seed, and inject 19.5M
3left and right, is closed the lid that feeds intake, exhaust-valve through preheating the pure calcium chloride solution of 75 ℃ of left and right and adding after appropriate organism adjusting material containing CaCl2144.91g/L.Open enamel still agitator and open thermal oil chuck fuel feeding valve, when liquid material is warmed up to 85 ℃ in still, in the liquid material of each still, with high-order isobaric metering, throwing liquid device respectively, injecting lentamente 1.2M
398% dense H
2sO
4and appropriate whisker growth substance; operating process needs about 30 minutes; the strong heat release of process (being the main auxiliary thermal source that in still, liquid material heats up); treat that material adds; in kettle, solution temperature is also elevated to and is greater than after 110 ℃; slightly stop; again whisker dispersion agent is added; complete after the operation of all throwing liquid, be taken up in order of priority all charging valves cut out, whole operating process will be careful the normal operation situation of equipment, material closely; through heat-insulation pressure keeping after 30 minutes; kettle chuck thermal oil oil drain valve open, and proceed to slow release and go out material process, process completes for about 40 minutes;
(6) heat consider, modified process: after release, obtain being with hot cotton-shaped slurry, after filtration and hot water countercurrent washing, then filter cake CaSO
41/2H
2o whisker is put into hot tub and is carried out modification, and modified stable completes CaSO clean after hot filter washing
41/2H
2o whisker filter cake send drying process;
(7) dry, finished product operation: heat is filtered to stable hemihydrate calcium sulfate crystal whisker after modification and be placed under the condition of 170-180 ℃ and be dried, (every still went out CaSO to dry output anhydrous calcium sulfate whisker product through 3.5 hours
4the about 3 tons of left and right of dry product), with every 5 stills, do one batch, 3 hours consuming time of every batch of operation, in equipment operation situation, every day (24 hours) anhydrous calcium sulfate whisker output 3 * 5 * 8=120 ton;
(8) reprocessing cycle ore leachate operation: every batch of 5 stills are with hot filtrate (containing countercurrent washing liquid) approximately to approach 96M after release
3(amount of liquid of loss during with release the volatilization of water vapour heat relevant), moves into container for storing liquid naturally cooling, can separate out 3.5 tons of left and right containing the CaSO of table water
42H
2o fiber, returns and does crystal seed use, and the regeneration of hydrochloric acid liquid of cold filter (containing countercurrent washing liquid) volume is approximately greater than 93M
3, sample examination is containing HCl82.24g/L, CaCl
219.75g/L., returning before soaking ore deposit and the hydrochloric acid of loss in process will being added, is slightly larger than after 86g/L the HCl content in solution, just can return to rhombspar breeze and soak ore deposit and use.
Claims (1)
1. the method for calcium sulfate crystal whiskers by dolomite made, the method comprises following processing step:
(1) grinding, soak ore deposit:with machinery, rhombspar is worn into breeze, rhombspar breeze is moved into and soaked in the container of ore deposit, add the hydrochloric acid soln of metering, after abundant stirring reaction is complete, by removal of impurities, filtration, make Ca
2+, Mg
2+muriate mixing solutions;
(2) de-Mg 2+ , filter:ca
2+, Mg
2+muriate mixing solutions, adds the lime emulsion of metering to make Ca
2+, Mg
2+separation, gained filtrate is the pure CaCl of concentrate after filtration
2solution;
(3) steam pressure, crystallization:by CaCl
2solution is placed in 110 ℃, the pressurized vessel of about 0.2MPa, inserts crystal modifier simultaneously, then adds the vitriol oil of metering, fully stirs, and through insulation, pressurize 30 minutes, makes hemihydrate calcium sulfate crystal whisker floss;
(4) modification, heat filter:after pressurized vessel release, by hemihydrate calcium sulfate crystal whisker floss solution, by band heat filtering and hot wash, water temperature is controlled at>=90 ℃, and filtration can obtain pure, dispersed good hemihydrate calcium sulfate crystal whisker;
(5) dry, finished product:heat is filtered to hemihydrate calcium sulfate crystal whisker after modification and be placed under the condition of 170-180 ℃ and be dried 3.5 hours, make anhydrous calcium sulfate whisker finished product;
It is characterized in that, in described modification, hot filtering technology, filter and minute to complete for four times: the first, under the environment of temperature>=90 ℃, filter, filter containing the hemihydrate calcium sulfate crystal whisker of raffinate; The second, by filtering containing the fully washing and filtering in the hot water of temperature>=90 ℃ of the hemihydrate calcium sulfate crystal whisker of raffinate, obtain pure hemihydrate calcium sulfate crystal whisker; The 3rd, the hemihydrate calcium sulfate crystal whisker of filtering purely, again by modification in the hot water of temperature>=90 ℃, washing and filtration, is obtained to the hemihydrate calcium sulfate crystal whisker after modification, filtrate is returned to second segment for hot wash and filtration; The 4th, the filtrate of gained after first paragraph and second segment filtration is merged to immigration container for storing liquid, after naturally cooling, separate out Dihydrate gypsum whiskers, after filter, Dihydrate gypsum whiskers is turned back in the pressurized vessel of making hemihydrate calcium sulfate crystal whisker and used as crystal seed, and gained filtrate is regeneration of hydrochloric acid liquid, and its main component is hydrochloric acid and remaining Ca
2+mixed acid solution, returning to circulation and soaking dolomite mineral.
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| CN104499040B (en) * | 2014-12-05 | 2017-06-30 | 上海宝冶钢渣综合开发实业有限公司 | A kind of method for preparing crystal whisker of gypsum |
| CN104674333A (en) * | 2015-03-17 | 2015-06-03 | 四川明鑫佳杰新材料有限责任公司 | Method for preparing nano-grade calcium sulfate crystal whisker from anhydrite |
| CN104928752B (en) * | 2015-07-06 | 2016-06-01 | 宁远县隆翔新型材料科技有限公司 | A kind of normal temperature prepares Dihydrate gypsum whiskers and normal pressure turns the method for anhydrous whisker |
| CN106006699B (en) * | 2016-07-07 | 2017-10-31 | 内蒙古金鼎新材料股份有限公司 | A kind of method for preparing high white superfine calcium sulfate powder |
| CN106319631B (en) * | 2016-08-30 | 2019-02-22 | 湖北永绍科技股份有限公司 | The joint disposal of a kind of sulfuric acid waste and hydrochloride waste utilizes method |
| CN108101080A (en) * | 2017-11-22 | 2018-06-01 | 浙江工业大学 | Method for preparing calcium-magnesium-aluminum crystal composite material from natural calcium magnesium carbonate mineral |
| CN110438568B (en) * | 2019-07-31 | 2024-02-27 | 一夫科技股份有限公司 | Method and system for producing gypsum whisker by using citric acid gypsum |
| WO2021116742A1 (en) * | 2019-12-13 | 2021-06-17 | Scarab Chile Spa | Method for obtaining an alkaline earth metal compound |
| CN113371749A (en) * | 2021-06-10 | 2021-09-10 | 西安吉利电子化工有限公司 | Method for treating calcium-containing sludge in semiconductor industry |
| CN114197028B (en) * | 2021-11-19 | 2023-04-28 | 四川康升晶须科技有限公司 | Continuous preparation method of calcium sulfate whisker |
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