Background technology
Wilkinite is a kind of clay rock, also claim montmorillonite clay rock, often containing a small amount of illite, kaolinite, halloysite, chlorite, zeolite, quartz, feldspar, calcite etc.; Be generally white, faint yellow, because iron-holder changes, be again light gray, light green, pink, brown red, brick red, grey black etc.; Tool is wax-like, earthy or oily luster; Loose as the soil that wilkinite has, the densification also having is hard.Main chemical compositions is silicon-dioxide, aluminium sesquioxide and water, also contains the elements such as iron, magnesium, calcium, sodium, potassium, Na
2o and CaO content are quite large on bentonitic physicochemical property and process technology performance impact.Wilkinite has strong water absorbability and swelling property, adsorbable 8~15 times to the water yield of own vol, volumetric expansion can reach several times to 30 times; In water medium, can be dispersed into as a form of gel and suspension, this medium solution has certain glutinousness, variability and oilness; There is stronger cation exchange capacity (CEC); Various gas, liquid, organic substance are had to certain adsorptive power, and maximal absorptive capacity can reach 5 times to the weight of self; The admixture of it and water, mud or fine sand has plasticity-and agglutinating value(of coal); There is surface-active acid bleaching soil (atlapulgite, natural bleaching soil-acidic white earth) and can adsorb colored ion.Wilkinite has very strong water absorbability, can adsorb and is equivalent to the water of 8 one 20 times of own vols and is expanded to 30 times; In water medium, can disperse to be soliquid, and have certain viscosity, thixotropy and oilness, the admixture of it and silt etc. has plasticity-and cohesiveness, has stronger cation exchange capacity (CEC) and adsorptive power.
What form in recent years take natural mineral wilkinite as raw material, the application performance of the nano level organobentonite of preparing through series of processes such as sodium, purification, organic modifications in the industries such as high performance plastics, rubber is greatly improved, and greatly met the requirement of modern industry to material.But natural mineral purity is lower, kind and the content distribution of its impurity are inhomogeneous, cause it in application, to be subject to certain restrictions.And when preparing nano level organobentonite, the very high wilkinite of most use purity is starting material, a large amount of low-grade bentonites is used as the raw material of the bulk products such as iron ore pellets, drilling mud, and added value is very low.At present, the organobentonite of producing is both at home and abroad used high-quality bentonite resource more, adopts cationic and amphoteric intercalator to prepare, stronger to the dependency of high-quality resource, and product application performance is subject to the impact of intercalator character.For the ubiquitous richness of adopting of bentonite ore, abandon poor, serious waste of resources and range of product is single, added value is low problem, take low-grade bentonite as resource, after the method for physical concentration is purified, carry out organic-treating, prepare nanometer level high purity organobentonite.The whole bag of tricks such as wilkinite manufacturer washes, centrifugal drying mud withdraw the high high-purity wilkinite composition of smectite content in bentonite ore, carry out the production of high-purity wilkinite material, carrying out of having is various organically-modified, to realize the good modified alta-mud of different application, producer is in the process of purifying, can produce a large amount of residue waste materials, Here it is wilkinite mine tailing.In mine tailing, smectite content is relatively low, and other intergrowth mineral still exists, and main chemical compositions is still silicon-dioxide, aluminium sesquioxide and water, also contains the elements such as iron, magnesium, calcium, sodium, potassium.
With wilkinite association nonmetallic tailings, attach most importance to, by mine tailing composition, phase, Technology characteristic and application technology are studied, set up and utilize wilkinite mine tailing to prepare the technical system of novel energy-conserving mineral products.
Trichroite (iolite) is a kind of silicate minerals, and it can be colourless, but conventionally has light blue or lilac, vitreous luster.Maximum characteristic is that thermal expansivity is little, is therefore widely used in pottery, glass industry, improves the ability of its anti-rapid heat cycle.Mullite (or Mo Naishi) is that a series of mineral that are comprised of aluminosilicate are referred to as, and these class mineral are more rare.Mullite is the mineral that aluminosilicate at high temperature generates, and during Heat artificially aluminosilicate, can form mullite.Natural mullite crystal is elongated needle-like and is radiation bunch shape.Mullite is a kind of refractory materials of high-quality, and it has the features such as expansion is even, thermal shock resistance is fabulous, load softening point is high, high temperature creep value is little, hardness is large, resistance to chemical corrosion is good, and mullite ore deposit is used to produce high-temperature refractory.
On market, there are synthetic trichroite and mullite now, and trichroite and mullite can be combined and obtain the kiln furnitures of dichroite-mullite over-all properties in kiln furnitures field, but because the cost of this bi-material itself is just very high, the kiln furnitures of preparing dichroite-mullite over-all properties, that cost is very high.Trichroite has very low thermal expansivity, good thermal shock stability, but resistance to elevated temperatures is not strong, the resistance to elevated temperatures of mullite is good, and heat shock resistance power is strong, but thermal shock resistance is good not, comprehensive both advantages, maximize favourable factors and minimize unfavourable ones, obtain the coefficient of expansion low, the dichroite-mullite product that resistance to elevated temperatures is strong.
But the body of current ubiquitous cordierite-mullite kiln furniture materials is close, be 1.75-2.15g/cm
3, product weight is large, and heat absorption is just many, and the consumption of raw material and fuel is just large.
Summary of the invention
For the defect in above-mentioned field, the present invention adopts wilkinite mine tailing, by adding other raw material auxiliary joining together, prepared lightweight cordierite-mullite kiln furniture materials, the kiln furnitures of preparation have composition characteristic and the brilliant item of dichroite-mullite, also possess the performance characteristics of dichroite-mullite simultaneously, turn waste into wealth, reduced production cost, and its body is close low, energy-efficient performance is good.
The lightweight cordierite-mullite kiln furniture materials of preparing with wilkinite mine tailing, its composition and weight percentage are: wilkinite mine tailing 25-35%, dichroite-mullite kiln furnitures waste material 15-25%, sillimanite 10-25%, chlorite 10-25%, low sodium alumina 5-10%, light-weight mullite material 15-25%, wood powder 2-5%, the 0.2-0.4% Mierocrystalline cellulose of additional aforementioned base materials weight, described wilkinite mine tailing is the tailing after the high high-purity wilkinite composition of smectite content in bentonite ore is withdrawn, and its composition is Al
2o
3content is 10-14%, MgO content 2-6%, wherein Na in low sodium alumina
2o content is less than 0.3%.
Wilkinite mine tailing 25%, light-weight mullite 21%, sillimanite 10%, chlorite 14%, low sodium alumina 8%, dichroite-mullite kiln furnitures waste material 18%, wood powder 4%, plus fiber element 0.4%.
The method of preparing dichroite-mullite kiln furnitures with wilkinite mine tailing, comprising the steps: 1) batch mixing adds water wet mixing after all raw materials are dry mixed, 2) ageing mixture packs in hopper the raw material after wet mixing into normal temperature and preserves more than 24 hours, 3) kiln furnitures product needed is pressed in moulding, kiln furnitures kiln base, 4 are made in compression moulding) kiln base is dry, and 5) high-temperature firing, under the high temperature of 1360-1400 ℃, insulation 6-10 hour;
During described wet mixing, press solids weight 6.0-8.0% external adding water;
When described kiln base is dry, adopt directly to enter in sealing chamber and protect and be dried; described protection be dried for prior to sealing indoor humidity be 60-95%; dry 16-24 hour at temperature 40-70 ℃, then be 30-60% in sealing indoor humidity, temperature is dry 24-36 hour at 110 ℃-150 ℃.
Described protection is dry adopts dry holder to support, and described dry holder is fence type closure plate face, and described plate face is greater than billet surface.
Described fence spacing is 70-120mm.
This material comprises aggregate (sillimanite, dichroite-mullite kiln furnitures waste material, light-weight mullite material, wood powder), substrate material (chlorite, low sodium alumina, wilkinite mine tailing) and admixture (Mierocrystalline cellulose), add and blend together pug after water and make according to a conventional method kiln furnitures.Wherein sillimanite chemical constitution is that silico-aluminate, crystal belong to rhombic nesosilicate mineral, Al
2o
362.9%, SiO
237.1%; The Al of light-weight mullite
2o
3content is 65-71%, SiO
2content is 20-27%, and body is close is 0.8-1.4g/cm
3(being different material from low aluminum-containing mullite in the past); The Al of dichroite-mullite kiln furnitures waste material
2o
3content is 35-46%, SiO
2content is 42-55%, MgO content 5.5-9.5%; In these three kinds of raw materials, its main component is Al
2o
3and SiO
2, be the main raw material that forms brilliant of mullite in the application; The Al of wilkinite mine tailing
2o
3content is 10-14%, and MgO content 2-6% has plasticity-and agglutinating value(of coal), the Al of chlorite after chance water
2o
3content is 12-18%, MgO content 29-33%, SiO
2content is 36-41%, aluminum oxide, and as auxiliary material, other desired characteristic of supplying raw materials, simultaneously to Al
2o
3and SiO
2content further adjust and supplement, it is the main raw material that forms brilliant of trichroite in the application, wood powder volatilizees and forms hole after firing, it is the effect that realizes product porous light, light-weight mullite is also the light material of porous series simultaneously, is the indispensable constitutive material of Realization of Product lightweight, and Mierocrystalline cellulose is realized the effect of tackiness agent, all raw materials are organically bonded together, become the kiln furnitures pug of homogeneous.
The organic assembling of above-mentioned raw materials, finally realizes the composition needs of dichroite-mullite, easily generates brilliant of brilliant of trichroite and mullite in sintering process, and trends towards partly forming more brilliant of trichroite in matrix, at aggregate, is partly the brilliant item of mullite.To realize the better dichroite-mullite kiln furnitures of over-all properties.
Mixing procedure: all raw materials, comprise after aggregate is dry mixed 3-5 minute with substrate material together with admixture etc. and add water wet mixing 5-8 minute.The raw material external adding water of compression moulding reaches 6.0-8.0%.
The raw material mixing packs hopper normal temperature into be preserved, and after the ageing mixture time is not less than 24 hours, could use.
Moulding process: compression moulding mode is carried out moulding kiln furnitures.
Compression moulding technique: single or double shaped by fluid pressure, according to required product size size, according to the shrinking percentage of this material approximately 1.2%, calculate the size of mould, for example to need length be 300mm to goods, and die size is that 300/ (1-1.2%)=303.6mm. forming pressure is according to 75-165kgf/cm
2be pressed, obtaining body close is 1.0--1.4g/cm
3product, according to demand, determine.In moulding process, cloth is wanted uniformity, can not local have expect many or expect few phenomenon, and cause the local body of whole goods close inconsistent, breakage in use easily appears local weak link and in product.
Drying process: the kiln furniture product moisture of extrusion moulding is large, needs to enter kiln after seasoning 2-3 days again and is dried, and can directly enter kiln and be dried after the moulding of compression moulding kiln furniture product, and kiln is that seal protection is dry, i.e. moisturizing is incubated again.In sealing chamber, humidity is 60-95%, dry 16-24 hour at temperature 40-70 ℃, then be 30-60% in humidity, temperature is dry 24-36 hour at 110 ℃-150 ℃.
Described protection is dry adopts dry holder to support, and described dry holder is fence type closure plate face, and described plate face is greater than billet surface.
Described fence spacing is 70-120mm.
Because base substrate is before entering klining system, must be dry through overprotection, as improper in protection drying conditions, easily cause this kiln furnitures product to deform, ftracture.As dry too fast, dehydration is too fast, easily makes base substrate occur crackle, as is dried slowly, affect working efficiency, if be dried not thoroughly, while firing, blank moisture content is large, and in sintering procedure, base substrate is easy to crack.If do not detect base substrate bending when protection is dry, because the sinuousness of each base substrate is different, bending position is different again, is easy to cause base substrate knee cracking during the vertical code of clipping, therefore protects dry condition extremely important.
Protection is that base substrate is placed in to dry holder upper support when dry, and its plate face should be greater than base substrate, and planeness is good, otherwise easily causes the periphery unfairness of base substrate, and dry holder, for fence type closure plate face, easily utilizes moisture loss, the preferred 70-120mm of interval of grid strip.Too wide, base substrate easily caves at fence gap location, and spacing is too little, is unfavorable for moisture loss.
Sintering technology: high-temperature firing, the high temperature that base substrate process is 1360-1400 ℃, insulation obtains the lightweight dichroite-mullite kiln furniture product of excellent property for 6-10 hour, can adopt the vertical code peace of clipping yard two kinds of modes to carry out setting and burn till.
The vertical code of clipping is with fitting strip, one pile of product to be clamped, and to found the mode of code, puts into kiln and fires, and has prevented from deforming at sintering procedure product.The preferred 100-200mm of thickness of one pile of product, too thin, base substrate number is few, and operation efficiency is low, and distortion probability is large, too thick, easily causes raw burn.During the vertical code of clipping, with plummet and level bar, detect its planeness.Base substrate after moulding need detect the homogeneity of its degree of compactness, the place that degree of compactness is bad, and the weak link of plate face namely, easy to crack in follow-up dry, sintering procedure, distortion.All these detection meanss are all to prevent that underproof product from flowing into next program, in order to avoid produce the wasting of resources.
Flat code burns till, and need to have the backing plate that planeness is very high to support, and backing plate plate face can not be less than the plate face size of burnt product.
Above-mentioned kiln furnitures product performance: body is close: 1.0-1.4g/cm
3; Normal temperature strength: 6-13Mpa; The coefficient of expansion (1000 ℃): 2.2--3.1 (x10-6K
-1); Refractoriness: 1400 ℃.This material bodies density is light, very energy-conservation, applicable as kiln furniture material.
The body of current ubiquitous cordierite-mullite kiln furniture materials is close is 1.75-2.15g/cm
3. product weight is large, and heat absorption is just many, and the consumption of raw material and fuel is just large.The light material of some other material, its coefficient of expansion is high, and thermal shock resistance is poor, and intensity is low, the inadaptable kiln furniture material that is used as.
The oikocryst item of this energy saving type lightweight cordierite-mullite kiln furniture materials is trichroite and mullite, the consisting of of the finished product: Al2O3:34-44%; SiO2:43-56%; MgO:5.5-9.5%.
This lightweight kiln furniture material, in its moulding process, green strength is higher, adapts to remove to unload, general light material, mechanical pressing difficulty, green strength is low, can not remove and unload.
This kiln furniture material has been applied wilkinite mine tailing and dichroite-mullite kiln furnitures waste material, and by the combination of said components, obtained the similar kiln furniture material of performance and dichroite-mullite, Mineral resources have effectively been utilized, real turns waste into wealth, and has also reduced the production cost of kiln furniture material, and this kiln furnitures product volume density is low simultaneously, belong to lightweight dichroite-mullite, energy-efficient performance is good.
Embodiment
Embodiment 1
Formula: wilkinite mine tailing 25%, light-weight mullite 21%, sillimanite 10%, chlorite 14%, low sodium alumina 8%, dichroite-mullite kiln furnitures waste material 18%, wood powder 4%, plus fiber element 0.4%.
Wilkinite mine tailing: the whole bag of tricks such as natural montmorillonite ore deposit is washed, centrifugal drying mud withdraw the high high-purity wilkinite composition of smectite content in bentonite ore, remaining waste material, the Al of wilkinite mine tailing
2o
3content is 10-14%, and MgO content 2-6% has plasticity-and agglutinating value(of coal) after chance water.
Batch mixing: by above-mentioned technique, be benchmark in 7%(solid contents) ratio external adding water, makes compound, sealing ageing mixture 24 hours.
Moulding: one side shaped by fluid pressure, use 140KGF/CM
2pressure carry out moulding, obtain the solid refractory slab green compact of 304*304*25.2mm, green compact hand can be moved, very solid.
Dry: by above-mentioned technique, to be dried.
Burn till: 4 one pile of rearings in tunnel furnace, at 1370 ℃, are incubated the lightweight slab kiln that is fired into 300*300*25mm for 10 hours.
Detect performance:
Above-mentioned data show, the more common dichroite-mullite goods of dichroite-mullite product volume density that the present invention makes are low, the coefficient of expansion is lower, the good thermal shock stability of product is described, meet the requirements, the composition requirement of the compound dichroite-mullite of product chemical composition, product performance are good, are the kiln furniture products of high-quality.
Inner construction analysis: as shown in Figure 1 and Figure 2.
The brilliant item of Fig. 1 Image Display, brilliant combination of brilliant of acicular mullite and cloud sheet shape trichroite is good.
Fig. 2 is that x-ray diffraction is analyzed collection of illustrative plates, and main brilliant is brilliant of trichroite and mullite.
Show that the product that the present invention makes is lightweight dichroite-mullite material.