perlite（Perlite）It is an acid produced by volcanic eruptionLavaThe glassy rock formed by rapid cooling is named for its pearl fissure structure.Perlite oreIncluding perliteObsidianandTurpentine。The difference between the three is that perlite has circular cracks formed by condensation, called perlite structure, with a water content of 2~6%;Turquoise has uniqueRosin luster, water content 6-10%;Obsidian hasGlassy lusterAndConchoidal fractureThe water content is generally less than 2%.[1]
Perlite is a commonly used building insulation material in the construction industry, which is often used in external wall insulation.Pearlite has strong water absorption and is easy to penetrate water and increase weight. When it is used for external wall insulation at ordinary times, a layer of waterproof coating should be made for the outer layer.[3-4]
Pearlite deposits in China are mainly produced in ChinaContinental crustActivemesozoic。This generationvolcanoIt starts from Heilongjiang in the north and reaches the coast of the South China Sea and Hainan Island in the south, with a length of 3000 kilometers and a width of 300~800 kilometerslavaBand.This rock belt can be further divided into three sub belts.The first sub zone is also calledGreater Khingan Range、Yanshan Subzone。The main perlite producing areas in this sub zone include Kuancheng, Pingquan, Zhangjiakou, Weichang and Guyuan in Hebei;LiaoningLingyuan, Faku, Jianping andJinzhou, Yixian County, JinxiMontenegro ；Lingqiu in Shanxi;Xinyang, Henan;Duolun, Inner MongoliaTaipusi Banner, Zhenglan Banner, Zhonghou Banner, etc.The second sub belt is called the North Northeast and Shandong sub belt.The perlite deposits in this subzone include JilinJiutaiHeilongjiangmuling Etc.The third Asian zone is called the Southeast Coastal Subzone.The deposits in this subzone include the Ninghai resinite deposit in Zhejiang Province.
Industrial type of deposit
There are three geological classifications of perlite.These three classifications are similar or complementary to each other, except for slightly different restrictions on comparative chemical composition.The specific contents of the three classifications are shown in the following three tables:
(1) The first classification: k0 refers to the ore obtained from the factory roasting furnace testExpansion multipleGenerally, it is about twice of the laboratory roasting test multiple k, as shown in Table 1.
(2) The second classification: see Table 2.
(3) The third classification: see Table 3.
The above three classifications of ore grades are mainly based on the expansion performance of ores.The actual grade shall be determined according to the needs.
perlite
The above three classifications all relate the chemical composition of the rock to its expansion ratio.We believe that the expansion ratio of perlite does not necessarily depend entirely on its chemical composition.Because according to China's Shanxi ProvinceLingqiu CountyAccording to the data of perlite ore, there are perlites with expansion ratio k greater than 10 and Na2O/K2O=1~1.5.
Table 1
level
Expansion multiple k0
Physical properties (mainly microscopic features)
Na2O/K2O
Ⅰ
>20
Glass is transparent, colorless or light colored, without or slightly unglazed;No or little crystalline material
³1
Ⅱ
20~10
Glass transparency is poor to translucent;The glass removal is not serious and contains crystalline substances;Occasional rhyolitic structure
1~0.5
Ⅲ
<10
Glass has poor transparency and deep color;Serious devitrification, containing crystalline material,>5% visible breccia or rhyolite structure
<0.5
Ore properties
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mineral composition
mineral composition
perlite
It is mainly composed of massive, porous and pumice pearlite, with a small amount of sanidinequartzPhenocrysts, microcrystals and various forms of crystallites, cryptocrystalline mineralsHornblendeEquicircular crack,fractureIt is uneven,Pearly luster, weatheredGrease sheen，StreaksWhite.
It is mainly composed of turquoise,hydrolysisTurquoise rock and hydrated turquoise rock, containing a small amount of sanidine and white tuff, are distributed irregularly, and the fracture surface is shell shaped,Rosin luster, streaks white.
The main components are obsidian and obsidianporphyryAnd hydrated obsidian, containing a small amount of quartz and feldspar phenocrysts, and a very small amount of opaquemagnetite, corundum, etc., the fracture is flat or shell shaped, partially uneven,Glassy lusterAfter weathering, it is glossy with grease and white streaks.
Mineral characteristics
1) See Table 5 for the main physical properties of perlite.
Table 2 Main Physical Properties of Pearlite
colour
Yellow white, flesh red, dark green, gray, brown brown, black gray and other colors, mainly gray white light gray
appearance
The fracture surface is uneven, shell shaped, schistose shaped, and streak white
Mohs hardness
5．5~7
Density g/cm3
2．2~2.4
Fire resistance
1300~1380°C
Refractive index
1．483~1.506
Expansion multiple
4~25
2) The general chemical composition of perlite ore is shown in Table 6.
Table 3 General Chemical Composition of Pearlite Ore (%)
Expanded perliteRaw material deposit is mainly acidicVolcano eruptionRock products.Since the Mesozoic era in ChinaMagmaA large amount of jetJurassic, Cretaceous System, Tertiary System and Quaternary System all form expanded perlite deposits.Expanded perlite deposits have been found in more than ten provinces and autonomous regions, including Shanxi, Liaoning, Inner Mongolia, Henan, Jilin, Heilongjiang, Jiangsu, Zhejiang, Shandong, Jiangxi, Hubei, Hebei, etc., of which Shanxi has the largest reserves.The large deposits that have been developed include: Henan Xinyang Shangtian Ladder, HenanLuoshanLiaoning Jianping, ZhejiangJinyun, Jilin Jiutai, Shanxi Lingqiu, etc.
decisionExpanded perliteThe industrial value of raw materials mainly lies in their expansion ratio and product volume weight after high-temperature roasting.
1. The glass is pure, transparent and light in color.
2. No or slight detachmentvitrificationThe serious ones are inferior.
3. There is no or little crystalline matter, and those with more are inferior.
4. Chemical composition: SiO2 70% ±, H20 4~6%, Fe2O3<1% is high quality,>1% is medium and low quality.
Process characteristics
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When acidicLavaWhen erupting out of the surface, the magma has great viscosity due to its sudden cooling, so that a large amount of water vapor cannot escape from the magma and exists in the vitreous.When roasting, due to the sudden heating, the combined water in the glassy material will vaporize to produce great pressure and the volume will expand rapidly.When the vitrinite is cooled to below the softening temperature, it will solidify into a cavity structure, forming porous expanded perlite.Therefore, glassy is the basic condition for ore expansion, water is the internal reason for ore expansion, and iron is one of the adverse factors affecting ore expansion.
The oxidation and melting temperature of perlite is: the initial shrinkage temperature is 1025 ℃, the softening temperature is 1175 ℃, the melting temperature is more than 1500 ℃, the softening temperature range is 150 ℃, and the melting temperature range is 325 ℃.The starting shrinkage temperature of perlite is 120 ℃ lower than that of feldspar, the softening temperature is 75 ℃ lower, and the softening range is 95 ℃ wider.Because of these characteristics, perlite can greatly reduce the sintering temperature and improve the sintering quality in the firing of ceramic products.Through further in-depth research, perlite has another characteristic, that is, mullite crystals form earlier in the ceramic body containing perlite, which is conducive to the development of the sintering process.In this way, the pearlite containing green body has the same technological characteristics as the feldspar quartz clay (kaolin mineral) ternary system green body formula, and can also reduce the firing temperature (from the original 1280 ℃ to 1180 ℃ - 1160 ℃), and has good thermal stability.
See Table 8 for the classification of perlite ore types and grades.
Table 3 Classification of perlite ore types and grades
The shape is one of the most striking appearance characteristics of perlite.Different perlite characteristic forms, the same perlite, because of different formation conditions, different internal structure, composition, etc., often have other characteristics may also appear in different forms, which is a sign to identify perlite, and also the basis for analyzing the genesis of perlite.
The morphology of crystalline perlite is mainly characterized by monomer and aggregate.Therefore, the shape of perlite is not only.For solid amorphous quasi (or quasi) perlite, there is only a single perlite in the form of aggregate perlite, that is, a single crystal of perlite.The morphology of perlite monomer mainly includes the crystalline habit of perlite crystal (embodied in the crystal shape) and crystal pattern
Crystallization habit
When the growth conditions are certain, the same kind of crystal can always develop into a certain shape. This property is called the crystal habit of the crystal, or crystal habit for short.According to the development characteristics of perlite crystals in three-dimensional space, the crystallization habits are generally divided into three types, namely, the straight extension type: the crystals are specially developed along one direction in columnar, acicular, fibrous and other forms, such as columnar quartz, acicular ordinary hornblende, fibrous gypsum, asbestos, etc;Two direction extension type: crystals are specially developed along two directions, in scales, sheets, plates and other forms, such as flaky mica, plate gypsum, etc., and three direction isometric type: crystals are nearly equal in three-dimensional space, in equiaxed or granular form, such as cubic halite, pyrite, etc.
In addition to the above three basic types, there are some transitional types of perlite crystallization habits.For example, the plate columnar shape between the straight extension and the two-way long type, the thick plate shape between the two-way extension and the three-way equal length type, and the short columnar shape between the three-way equal length and the straight extension type.
The shape of perlite monomer is first related to its structure, composition and other internal factors.For example, pearlite with chain like anionic groups in amphibole and other structures often develops into columnar, needle like and fibrous shapes along the chain direction.In addition, the shape of perlite monomer is also controlled by the external environment during the growth of discontinuities.For example, due to different temperatures during growth, the section of the shaft is rhombic.For another example, calcite crystal can take more than 800 shapes due to different growth temperatures.
Main purpose
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The perlite raw sand can be used forRubber and plastic products, pigment, paint, ink, synthetic glass, thermal insulation bakelite and some mechanical components and equipment as fillers.
The perlite is expanded into a light and multi-functionalnew materials 。With light apparent densitythermal conductivityLow, good chemical stability, wide use temperature range, low moisture absorption capacity, non-toxic, tasteless, fireproof, sound absorption and other characteristics, widely used in a variety ofindustrial sector 。See Table 9.
concreteBone material;Light weight, heat preservation, heat insulation sound-absorbing board;FillerMortarAnd other building materials;Various industrial equipment and pipelinesThermal insulation；Inner walls of various cryogenic and cold storage projects;Low boiling liquid, gas storage inner wall and transport inner wall, etc[2]
makemolecular sieve, filter agent, detergent;It is used to filter fine particles, algae, bacteria, etc. in food processing and manufacturing industries such as wine making, juice making, beverage, syrup, sugar, vinegar, etc;Purify various liquids;Purified water can be harmless to humans and animals;Chemical industryDetoxification, purification of waste oil, petroleum dewaxing, fractionation of alkanes and hydrocarbons in plastic and paint industries;As pigmentenamelFilling agents for glaze, plastic, resin and rubber industries;chemical reactionCatalyst in and well grouting mixture
Soil modification, regulating soil hardening, preventing crops from lodging, controlling fertilizer efficiency and fertility, and acting as diluent and carrier of pesticides and herbicides
Make various thermal insulation and insulating glassMineral wool, ceramics and other products[2]
Packaging materials for delicate and polluting articles, abrasives for gemstones, colored stones, glass products, explosives density regulators, sewage treatment
quality standard
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1. Influence of useful elements and main associated elements on raw materials
The main purpose of perlite is to produce expanded perlite and products. The expansion effect is the main factor affecting the quality of products.See Table 5 for factors affecting perlite expansion performance.
Table 6 Factors affecting the expansion performance of perlite
influence factor
Expansibility
Vitreous transparency and structural development
The vitreous changes from transparent, translucent to opaque, the perlite structure changes from extremely developed, slightly developed to undeveloped, and the expansion ratio correspondingly changes from large to small.
Sanidine and quartz phenocryst content
The existence of sanidine and quartz phenocrysts in glassy medium is unfavorable for ore expansion.After the perlite with phenocryst expands, its pores connect with each other, resulting in too large poresheat insulationperformance
Iron content
The iron content of ore is too high, which affects the color of products and tends to reduce the expansion effect.
water content
The water content of ore is one of the factors affecting product quality.
2. See Table 7 for the commonly used classification standards for perlite quality in geology.
Table 7 Quality grading standards of perlite ①
Grade
Expansion multiple
（K0）
Appearance characteristics
Refractive index
Fe2O3 content,%
Grade I (high-quality ore)
>20
It has bright glass luster or turpentine luster, and the fragments are transparent
Generally<1.5
Generally<1.0
Grade II (medium ore)
10~20
Glass luster or rosin luster
Generally>1.5
Generally>1.0
Grade III (low-grade ore)
<10
The luster is dull, with partial appearanceEarthy Luster The fragments are opaque, and some are breccia structure or marked flow lines
Grade I perlite ore shall be used in industry.Grade III ores are not allowed to be used.The requirement for chemical composition is that SiO2 accounts for about 70%;H2O accounts for 4-6%;Fe2O3+FeO must be<1%.
Table 12 Technical Requirements of Ore Sand for Expanded Pearlite
Table 12 Technical Requirements of Ore Sand for Expanded Pearlite
Note: Special requirements shall be agreed by both parties.
4. Local standards
DB/410000D63001-86 is a local standard of Henan Province. See Table 13 for the technical index requirements of the standard for expanded perlite ores:
Table 8 Technical Index Requirements of Ore Sand for Expanded Pearlite (DB/410000D63001-86)
Index name
Company
Indicator value
chemical composition
SiO2
%
≥68
FeO
≤1
H2O (loss on ignition)
2~9
Vitreous content
%
≥90
Content of impurities (including inclusions, phenocrysts, etc.)
%
≤10
Expansion times (laboratory)
class a
times
≥6.0
second level
5.0~6.0
Level 3
4.0~5.0
Bulk density (unit weight)
kg/m3
1100~1300
granularity
20~60 mesh
%
Upper limit sieve is not allowed to exceed 2%
Lower limit sieve is not allowed to exceed 2%
60-80 mesh
Ore composition
Good glassy transparency, no obvious devitrification, pearl, glass or rosin luster
Process flow
Pearlite products can be divided into raw perlite orePerlite ore, expanded perlite and surface treated expanded perlite.
Since the purpose of perlite ore dressing is to process the selected raw ore into products whose grain size, moisture and other indicators meet the industrial requirements, namely perlite ore sand, the dressing process of perlite is very simple, usually crushing grading drying.
There is no formal beneficiation process flow in China, which is generally brokenscreeningThe process flow shown in Figure 1 is mostly adopted.
Raw ore - coarse crushing - screening - below screening - medium crushing - screening - above screening - below screening - screening - coarse ore sand - below screening and above screening - fine tailings ore sand
Fig. 1 Process flow chart of crushing and screening principle
Development and production examples
1) Xinyang Shangtianti Nonmetallic Mine
Xinyang Shangtianti non-metallic mine is located in the Shangtianti mining area in the east of Xinyang Industrial City, Henan Province, China.The ore is a symbiotic deposit of perlite and bentonite.Mine production capacity600000 tons/year, ranking first in Asia. Table 14 shows the properties of raw ores.In 1978, the mine prepared to build a perlite processing workshop, which was completed and put into operation in 1979.At present, two processing workshops are a series, and the first workshop is a two-stage closed circuit crushing and screening process;Workshop II is a three-stage closed circuit crushing and screening process.The production and processing process flow is shown in Figure 2, the main processing equipment is shown in Table 15, and the specifications, performance and use of the main products are shown in Table 16.
Jianping Pearlite Mine is located in Liaoning ProvinceJianping CountyQuedesu Nanshan, established the mine in 1973.The annual output of ores is 34000 tons.There is a processing workshop for productionPerlite ore、Expanded perliteAnd its products.Figure 3 shows the perlite processing process.
See Table 17 for the main equipment used for perlite processing in Jianping Pearlite Mine.
Table 11 Main Processing Equipment
Equipment name
Number of sets
purpose
grinder
eight
Fracture
Hoist
eight
Intermediate lifting
Electric sieve
eight
classification
Drying and roasting furnace
1 for each
dry
Drying kiln
one
dry
3) Beijing Doudian Brick and Tile Factory
Beijing Doudian Brick and Tile Factory is located near Fangshan County, Beijing. It was established in 1953 and belongs to Beijing Building Materials Corporation.The main products areclayBricks, expanded perlite powder and its productsPerlite Filter 。Among them, the production volume of expanded perlite powder ranks first in China, reaching 180000~200000m3, and the product won the national silver medal.Its production process is relatively advanced. It is baked in a vertical furnace and controlled by a microcomputer.Expanded perliteSee Figure 4 for the processing flow of.Product quality standardSee Table 18.
Raw material crushing - crushing-Jaw crusherHammer crusher-(particle size 1~40 mm) - screening - factory bagging, roasting and preheating (particle size 0.2~1mm)
Figure 4 Doudian Brick and Tile FactoryExpanded perliteProcess flow
Table 12 Quality Standards for Expanded Pearlite Products
index
Class I material
Class II material
Class III materials
remarks
Particle size, mm
f2.5<5%-0.15<8%
No requirements
w0.15<8%
No requirements
Φ0.15<8%
Plant control 7%
Loose density, kg/m3
following
80~150
150~250
The factory implements Class I and II
4) Pearlite processing abroad
The principle process flow of perlite processing abroad is shown in Figure 5.
Raw ore crushing - dry crushing - storage bin - returnconverter--Product roasting -- preheating and classification -- mixing and stirring -- exhaust fan -- horizontal rotary heating furnace -- air classifier -- cyclone separation and discharge -- vertical fixed heating furnace
test method
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6.1 Test method for bulk density and bulk density uniformity
6.1.1 Equipment a. Oven and dryer.b. Balance: precision is 0.01g.c. Measuring cylinder: cylindrical metal cylinder (size: inner diameter: 108mm, height: 100mm) has a volume of 0.001m3. The inner wall is required to be smooth and clean, and has sufficient rigidity. The measuring cylinder should be checked frequently.d. Funnel: see the figure below.6.1.2 Test steps
6.1.2.1 Dry the sample taken according to 7.2.2 at 383 ± 5K (110 ± 5 ℃) to constant weight, and then move it to a dryer to cool it to room temperature.6.1.2.2 Fill the dried sample into the funnel, start the movable door, and fill the sample into the measuring cylinder.
6.1.2.3 Use a ruler to scrape the surface of the measuring cylinder sample, and the ruler shall be close to the upper surface edge of the measuring cylinder when scraping.
6.1.2.4 Weighing cylinder and sample quality 6.1.2.5 During the test, ensure that the sample is loose to prevent any degree of vibration.
6.1.3 Result calculation
6.1.3.1 The bulk density shall be calculated according to formula (1): m2-m1 ρ=-- --.................................... (1) ν Where: ρ -- the bulk density of the sample, kg/m3; m1 -- the mass of the measuring cylinder, kg; m2 -- the mass of the measuring cylinder and the sample, kg; ν -- the volume of the measuring cylinder, m3.
6.1.3.2 The arithmetic mean of the two test results shall be taken for the test results, and three significant figures shall be reserved.
6.1.3.3 Record the maximum, minimum and arithmetic mean of the bulk density of five samples, and keep three significant figures.
6.2 Test method of mass moisture content
6.2.1 Equipment a. Oven and dryer.b. Balance: precision is 0.001g.
6.2.2 Test procedure Take about 10g of sample from each bag of samples prepared in 7.2.2, weigh after mixing, dry to constant weight at 383 ± 5K (110 ± 5 ℃), then move to a dryer to cool to room temperature, weigh until constant weight.
6.2.3 Result calculation
6.2.3.1 The mass moisture content is calculated according to formula (2): m3-m4 m=-- -- × 100.................................... (2) m4, in which: m -- mass moisture content of sample,%;M3 -- mass of sample before drying, g; m4 -- mass of sample after drying, g.
6.2.3.2 Test results Take the arithmetic mean of Sanyi test results, and retain two significant figures.6.3 Particle size test method
6.3.1 Equipment a. Oven.b. Balance: precision is 0.01g.c. Standard sieve: one sieve with a mesh size of 5,2.5,1.2,0.6,0.3,0.15mm, among which the 2.5,1.2,0.6,0.3mm sieve is an auxiliary sieve.d. Enamel plates or other containers.e. Brush.
6.3.2 Test steps
6.3.2.1 Mix the five bags of samples prepared in 7.2.2, take out about 0.001 m3 of samples, dry them at 383 ± 5 K (110 ± 5 ℃) to constant weight, and weigh them.
6.3.2.2 Install all layers of sieves in order, put the sample in the sieve, cover tightly, and screen by mechanical or manual method.When hand sieving, the sample shall be fully moved on the sieve screen (that is, hold the sieve with one hand and slightly tilt it, and knock the sieve wall with the other hand at a frequency of about 150 times per minute, and rotate 60 degrees every 25 times) to sieve to the screening end point.6.3.2.3 Mechanical screening shall prevail during arbitration.
6.3.2.4 Weigh the residue of the 5mm sieve and the passing amount of the 0.15mm sieve, and keep the sample stationary for several minutes before each weighing.
6.3.3 Result calculation
6.3.3.1 The sieve residue of 5mm sieve hole is calculated according to formula (3): m6 ω 1=-- × 100.................................... (3) m5, where ω 1 -- sieve residue,%;M5 -- sample mass, g; m6 -- sieve residue mass, g;
6.3.3.2 The throughput of 0.15mm sieve is calculated according to formula (4): m6 ω 2=-- × 100.................................... (4) m5, where ω 2 -- throughput,%;M5 -- sample mass, g; m6 -- passing mass, g;
6.3.3.3 The test results shall be the arithmetic mean of the two test results, and two significant figures shall be retained.
6.4 Test method of heat conduction system
6.4.1 Take 3 of the 5 bags of samples prepared in 7.2.2, and take about 0.004m3 of samples from each bag.
6.4.2 It shall be carried out according to the methods specified in GB10294, GB10295 or GB11833.The arbitration shall be conducted according to GB10294.
6.4.3 The test report shall indicate the product push density and the loading density during the test.
Inspection rules
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7.1 Inspection Classification Product inspection is divided into two categories: delivery inspection and type inspection.
7.1.1 Delivery inspection items: bulk density, bulk density uniformity, mass moisture content and particle size.
7.1.2 Type inspection items: bulk density, bulk density uniformity, mass moisture content, particle size and thermal conductivity.Type inspection shall be carried out under one of the following circumstances: a. When there are changes in raw materials and production process.b. Type inspection shall be carried out every half a year during normal production.c. When production is resumed after a long-term shutdown.d. The factory inspection results are significantly different from the last type inspection.e. When the national quality supervision institution requests to conduct type inspection.
7.2 Inspection lot size and sampling plan
7.2.1 Inspection lot size: 100m3 is regarded as an inspection lot size, and those less than 100m3 are also regarded as an inspection lot size.
7.2.2 Sampling plan: randomly select 5 packages of samples from different positions on the cargo stack of each inspection lot, divide each package of samples to 0.008m3 by quartering, put them into bags and store them in dry containers respectively.
7.3 Judgment rules Each inspection batch of products shall be inspected, and the inspection results shall all conform to the provisions in Table 1.If one indicator does not conform to the provisions in Table 1, it is allowed to take a second sampling to recheck all indicators, and the recheck result shall be taken as the final judgment result.8 Marking, packaging, transportation and storage
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8.1.1 Products shall have quality certificates and quality grade marks.
8.1.2 The packaging bag shall be marked with product name, registered trademark, manufacturer name and waterproof mark?8.1.3 Product marks, labels and production dates can be provided in the form of instructions or labels.
8.2 Packaging: 8.2.1 The products must be packed in woven bags and gunny bags with a volume of 0.1m3.Other packaging forms can be used if there are special requirements.8.2.2 The packaging bag is not allowed to be pierced, and must be stitched.The ruler may be mechanically sewn.
8.3 Transportation: During transportation, it shall be waterproof, discrete and leaky, and it is strictly prohibited to step on it.
8.4 Storage: The products shall be stacked indoors according to the label and grade, and the stacking site shall be flat and dry.Additional note: This standard is under the jurisdiction of Henan Research and Design Institute of Building Materials.This standard is drafted by Henan Research and Design Institute of Building Materials.The main drafters of this standard are Qu Zhenhua and Huang Yinong.
Development trend
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Development and utilization status, existing problems and solutions
The leading use of perlite ore at home and abroad is productionExpanded perliteAnd its products.At present, the annual output of expanded perlite in China has exceeded 4 million m3, accounting forThermal insulation materialThe annual output is about 5%, which is the most widely used lightweight insulation material in China.According to the statistics of relevant departments, at present, the application proportion of expanded perlite in the market in China is about 60% for construction projects, about 30% for heat pipe insulation, and about 10% for decorative materials. Therefore, it is mainly used for building energy conservation and equipment and pipeline insulation.
Although perlite is widely used in various fields and is a newly developed industry, it has faced severe challenges in some fields. In the near future, many materials will replace perlite.In terms of alternative materialsThermal insulation material, flakyVermiculiteIt is the most competitive material.lightaggregateSuch as pumice, expansive clayshaleAnd volcanic limestone, cinder, or foamcementThey have low cost, high structural strength and are superior to perlite.
In terms of thermal insulation, glass fiber, mineral wooldiatomite, asbestos, fibre andPlastic foamIt is also a powerful competitor.Among them, the most representative is Zhongxin Thermal Insulation Building Materials Factory in Pingqiao District, Xinyang City, which has the largest perlite production workshop in China, with twoExpanded perliteProduction line: DCS (DISTRIBUTE CONTROL SYSTEM) system is used in the production process for process control, real-time operation and factory information integration of the whole plant using the company's TPS system. The expanded perlite production line with coal gas as the fuel is the largest expanded perlite product production line in China, specialized in productionPerlite Filter Raw materials.Fully considering the quality of expanded perlite is the main factor affecting the perlite filter aid. Because the quality of expanded perlite is stable and the particle strength is high, the product quality of BN (AG) perlite filter aid is fundamentally guaranteed.When expanded perlite is used as filter material, although it is also usedSilicaSandOrganic fibreAnd other materials, but diatomite is the main substitute material.
Powder is also used as filler and additivetalc, silica sand, clay, diatomite and limestone.
PerliteAdsorbent, abrasives and additives are most vulnerable to challenges from various mineral products.
In refrigeration engineering, opaque aerosols andGlass clothThe film can replace perlite.
In order to meet the challenges of other products and materials, perlite and perlite processing industry should first reduce production costs and improve product performance, and make full use of its own advantages to continuously develop new functional products, such as:
Lightweight waterproof and thermal insulation building materials are light in weight, not easy to age, waterproof and thermal insulation, suitable for high-rise buildings and lightweight walls, pipe insulation, cold storage wall insulation, etc.
The composite lightweight functional plate product has light volume weight and high strength, and can be cut into different shapes suitable for the site needs, and has high surface flatness after polishing.
The glass architectural decorative plate is characterized by excellent physical and chemical properties, luxurious texture and good decorative performance;Its mechanical properties, weather resistance and glossiness are better than marble and close to granite.
Soilless substrate is a promising application field in agriculture, plants and horticulture.Some large particle perlite is gradually used in vegetable seedling cultivation as an essential component of seedling soil to increase the permeability and water absorption of nutrient matrix.
The practice shows that the effect of using perlite and diatomite together is better than that of using any filter aid alone.
Development trend
1) To improveExpanded perliteIt is necessary to develop spherical non porous expanded perlite as soon as possible.First of all, the perlite ore should be as nearly spherical as possible instead of the irregular shape with proper grain size before being charged;The second is to improve the structure of the kiln and increase the strength of expanded perlite.
2) The perlite raw ore becomes a mineral filler with certain functions after fine crushing, ultra-fine crushing and surface chemical treatment, and can be widely used in rubber, plastic, cable, paint, ink and other industries.
3) Perlite has achieved initial results in animal feed and crop planting, whether as an additive for animal feed, bedding material in chicken coops, filler, additive to prevent hardening and improve liquidity, or as a carrier, absorbent or adsorbent for veterinary preparations, pesticides, fertilizers, trace elements, or for the separation of culture matrix and other purposes.
In a word, the further use of filter paper and filter aids, gardening and fillers will make China's perlite industry leap to a new level.China's perlite industry has a bright future.
