CN105481538B - Environment-friendly treatment process for red mud - Google Patents
Environment-friendly treatment process for red mud Download PDFInfo
- Publication number
- CN105481538B CN105481538B CN201510895329.3A CN201510895329A CN105481538B CN 105481538 B CN105481538 B CN 105481538B CN 201510895329 A CN201510895329 A CN 201510895329A CN 105481538 B CN105481538 B CN 105481538B
- Authority
- CN
- China
- Prior art keywords
- red mud
- powder
- barren
- environment
- treatment process
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
- C05G3/00—Mixtures of one or more fertilisers with additives not having a specially fertilising activity
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05D—INORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
- C05D3/00—Calcareous fertilisers
- C05D3/02—Calcareous fertilisers from limestone, calcium carbonate, calcium hydrate, slaked lime, calcium oxide, waste calcium products
Abstract
The invention provides an environment-friendly treatment process of red mud, which comprises the following steps: extruding the neutralized wet red mud, cutting into segments, mixing the mixed powder of at least one of mineral fiber and plant debris and barren powder with volcanic ash property with the segments to form red mud blocks, and using the redundant mixed powder which is not adhered to the red mud blocks as a powder bed for drying; when the red mud agglomerate is dried to lose plasticity, lime, carbide slag and the red mud agglomerate are mixed, at the moment, the barren powder with the volcanic ash property and the lime generate volcanic ash reaction and are gradually converted into volcanic ash cement materials to embed the red mud agglomerate, and the adhered grass wood chips or waste paper pulp or paper sludge are used as reinforcing rib materials; and loosening and mixing the sandy loam and the embedded red mud clusters to obtain the seaside greening soil material. The invention solves the problem of difficult drying of the red mud by increasing the specific surface area of the red mud lumps and the water absorption of the barren materials, also solves the problem of dust during transportation and transportation of the dried red mud, and can realize large-scale resource optimization.
Description
[ technical field ] A method for producing a semiconductor device
The invention relates to an environment-friendly treatment process of red mud.
[ background of the invention ]
The red mud is polluting waste residue discharged when aluminum ions are extracted in the aluminum production industry and the like, and generally 1.0-2.0 tons of red mud are additionally generated every 1 ton of aluminum oxide is produced. China, as the 4 th alumina producing country in the world, discharges up to millions of tons of red mud every year. A large amount of red mud cannot be fully and effectively utilized, and can only be stacked by a large-area yard, thereby occupying a large amount of land and causing serious pollution to the environment. The red mud produced in the world is about 7000 million tons, and the red mud produced in China is more than 3000 million tons every year. The production of a large amount of red mud has caused direct and indirect influences on the production and life of human beings in many aspects, so the yield and the harm of the red mud are reduced to the maximum extent, and the realization of multi-channel and large-quantity resource utilization is urgent.
The pH value of the red mud is very high, wherein: the pH value of the leaching solution is 12.1-13.0, and the fluoride content is 11.5 mg.L-1-26.7mg·L-1(ii) a The pH value of the red mud is 10.29-11.83, and the fluoride content is 4.89 mg.L-1-8.6mg·L-1. According to the GB 5058-85 standard for controlling pollution of solid waste in nonferrous metal industry, the pH value of red mud is less than 12.5, and the fluoride content is less than 50 mg.L-1Therefore, the red mud belongs to common solid waste residue. However, the pH value of the red mud attaching solution is more than 12.5, and the fluoride content is less than 50 mg.L-1The comprehensive discharge of sewage is classified into standard exceeding waste water, so that the red mud (containing the attached liquid) belongs to harmful waste residues (strong alkaline soil).
At present, the invention patents of red mud resource utilization are numerous, but several common methods are as follows:
1. the cement is manufactured, and the cement is rarely used at present due to the strict requirement of new national cement standards on alkali content.
2. The method has good feasibility by mixing fly ash, lime and the like and using the red mud as an alkaline promoter, but the red mud in the formula is less in dosage, so that the problem of red mud elimination is difficult to solve.
3. Other substances are doped to be used as the baked bricks, the dosage is strictly controlled to be below 30 percent and is limited by the current restriction of baking bricks, the prospect is poor, and the frosting is serious without practical value when a plurality of bricks are used.
4. Mine filling is good in effect, but red mud is difficult to carry and is severely limited.
5. The method is used as an inert filler in the ceramic and plastic industries, but the method has high feasibility, is troublesome in red mud pretreatment, has more replaceable substances, also influences the material quality, and has no obvious raw material advantages.
6. The desulfurizer can be used as a desulfurizer, and has the problems of small using amount, poor fluidity and large amount of waste residues, and the factory reaction is not as practical as lime slurry or waste alkaline water.
In some seashore cities, small and medium-sized factories often extract sodium aluminate from bauxite as raw materials of washing products, and the factories produce about ten thousand tons of red mud each year as a byproduct, and the red mud is usually neutralized by using pickling waste liquor and then placed. The treated red mud contains a large amount of salt and ferric hydroxide, is extremely difficult to dry, and is difficult to realize large-scale resource utilization due to quantity limitation, so that a resource utilization way matched with the scale is required to be developed.
The red mud briquette has the characteristic that the red mud briquette cannot be loosened and disintegrated when meeting water due to poor permeability after being dried, and the characteristic is more obvious due to the fact that the red mud briquette contains a large amount of ferric hydroxide which can hardly absorb water once being neutralized and dried by using the pickling waste liquid. This feature can be fully utilized.
[ summary of the invention ]
The technical problem to be solved by the invention is to provide an environment-friendly treatment process for red mud, which solves the problem of extremely difficult drying of the red mud by increasing the specific surface area of red mud lumps and the water absorption of barren materials, solves the problem of dust during transportation and transportation of the dried red mud, and can realize large-scale resource optimization.
The invention is realized by the following steps:
an environment-friendly treatment process for red mud, which comprises the following steps:
extruding the neutralized wet red mud, cutting into segments, mixing at least one of mineral fiber and plant debris and barren powder with volcanic ash property with the mixed powder to form red mud blocks or pressed blanks, and using the redundant mixed powder which is not adhered to the red mud blocks as a powder bed for drying;
secondly, when the red mud block mass is dried to lose plasticity, raking out and embedding, namely mixing at least one of lime, calcium silicate cement and carbide slag with the red mud block mass, wherein at the moment, the barren powder with the volcanic ash property and calcium ions generate volcanic ash reaction under alkalinity, the barren powder is gradually converted into volcanic ash cement material to embed red mud block, and the adhered grass wood dust or waste paper pulp or paper making sludge is used as a reinforcing rib material;
and step three, loosely mixing sandy loam and the embedded red mud clusters to obtain the seaside greening soil material.
Further, the neutralized wet red mud in the step one is the red mud neutralized by the pickling waste liquid.
Further, the weight ratio of each component in the first step is as follows: neutralized wet red mud: barren powder with pozzolanic properties: at least one of the mineral fiber and the plant debris is 100: 10-300: 1-10.
Further, the barren powder with the volcanic ash property is at least one of fly ash, coal slag ash and steel slag ash.
Further, the weight ratio of the red mud agglomerate to at least one of lime, calcium silicate cement and carbide slag in the second step is 100: 2-8.
Further, the weight ratio of the sandy loam to the embedded red mud clusters in the third step is 100: 30-600.
Further, the mineral fiber in the first step is at least one of peat chips or rock wool glass fibers, and the plant chips are at least one of grass wood chips, waste paper pulp or paper sludge.
The invention has the following advantages:
the process solves the problem of extremely difficult drying of the red mud by increasing the specific surface area of the red mud lumps and the water absorption of the barren materials, also solves the problem of dust during transportation and transportation of the dried red mud, and can realize large-scale resource optimization. In a word, the invention has high drying efficiency, low operation cost and good economic and environmental benefits.
[ detailed description ] embodiments
The invention relates to an environment-friendly treatment process of red mud, which comprises the following process steps:
step one, extruding and cutting the neutralized wet red mud, mixing at least one of barren powder with volcanic ash property such as coal slag ash, fly ash, steel slag powder and the like and peat scraps, rock wool glass fibers, grass and wood scraps, waste paper pulp or paper sludge with the barren powder and the peat scraps, the rock wool glass fibers, the grass and wood scraps, the waste paper pulp or the paper sludge to form red mud briquettes basically without viscosity, wherein the weight ratio of the red mud briquettes is controlled as the wet red mud briquettes: one or more of fly ash, coal slag ash and steel slag powder: at least one of the plant chips, the waste paper pulp or the paper sludge is 100: 10-300: 1-10, the cinder ash and the fly ash are generally used as bulk powder, and the particle size is not particularly selected. The fly ash and the cinder ash with large mixture ratio are generally used, and the surplus barren powder which is not adhered to the red mud lumps is also used as a powder bed for drying. The mixture can be stacked and dried, is not easy to bond and collapse due to gravity, and is not easy to cause salt and alkali migration to pollute a storage yard due to thick capillary structure. The step solves the problem of extremely difficult drying of the red mud by increasing the specific surface area of the red mud lumps and the water absorption of the barren materials.
Step two, when the red mud pellets are dry and lose plasticity basically, raking out the pellets for embedding treatment, namely mixing at least one of lime, calcium silicate cement and carbide slag with the red mud pellets, wherein the red mud pellets are usually half-dried: the weight ratio of lime, calcium silicate cement, carbide slag and the like is 100:2-8, and at the moment, the fly ash, the coal slag ash, the steel slag powder and the like and calcium ions are subjected to a pozzolan reaction under alkalinity and are gradually converted into pozzolan cement materials to embed red mud lumps, so that the pozzolan cement materials have certain compressive and flexural strength. And the adhered grass and wood scraps, waste paper pulp and the like are used as reinforcing rib materials. The residual coal slag ash, fly ash, grass and wood chippings and the like are continuously used in the next round. The step solves the problem of dust during transportation and transportation of the dry red mud.
Non-pozzolanic materials such as portland cement, magnesite cement, aluminate cement and the like are not usually used, on one hand, the cement has short weather resistance, on the other hand, the setting speed of the cement is difficult to match with the drying and embedding time scale of the red mud mass, the red mud mass is easy to form hollow mass due to drying and shrinkage, and the transportation and the subsequent use are difficult.
The red mud block with the surface embedded with the pozzolana cementitious substance contains a large amount of salt, but the release speed is slow, and experiments prove that the red mud block is suitable for being used as a greening material for seashore areas or saline-alkali areas.
Step three, mixing sand, coal slag fragments and the like with soil (such as black soil, various kinds of clay doped with stabilized domestic sludge and the like) with more humus in advance to form sandy loam (sandy loam in the traditional geological sense), and then loosely mixing with embedded red mud agglomerates and the like, wherein the mixing ratio is controlled in the sandy loam: the weight ratio of the embedding red mud block mass is 100: 30-600. The concrete proportion is determined according to the application, the embedded red mud blocks with high proportion are used as tuyere soil or seaside wind-proof wall often with runoff water when the wind-break wall is manufactured, and the red mud blocks with low proportion are used for greening the soil. The greening soil material with the structure has strong wind erosion and water erosion resistance due to the existence of large-particle embedded red mud pellets; because the material has good air permeability and large pores, the salt of the red mud agglomerate released slowly can be smoothly discharged to the alkali discharge ditch. Because a large amount of sandy loam exists among the red mud pellets, the development of plant root systems is facilitated. Although the red mud briquette has the characteristic of not being soft and disintegrated when meeting water after being dried, particularly the red mud neutralized by the pickling waste liquid contains a large amount of ferric hydroxide which is basically non-absorbent after being dried, the shell of the embedded pozzolana cement is not easy to damage, but the water retention capacity of the red mud briquette is still obviously higher than that of traditional materials for resisting wind erosion and surface runoff scouring, such as stones, shells and the like, and the supply of water vapor in soil can be ensured.
Through the process, the red mud can be effectively used for greening the sandy soil on the seashore, the embedded red mud blocks play the beneficial roles of water retention and wind erosion and water erosion resistance for a certain period of time, after the embedded red mud blocks are used for a long time and are broken, green soil plants grow out to realize water and soil protection because the salt is basically discharged, so that the residual salt has no obvious harm to the ecology of the protected land, and the disintegrated clay-shaped fine particles rich in minerals have obvious benefits for the transformation of the sandy land. Traditional materials such as stones and shells which cannot be damaged for a long time and are resistant to wind erosion and surface runoff scouring have certain influence on the good development of the plant root system.
The present invention will be further described with reference to the following examples.
Example 1:
red mud from detergent factory in Fujian Shishi is neutralized with waste pickling liquid. The product is yellow brown high viscosity mud, has water content of more than 60%, and is difficult to transport and dispose.
The neutralized red mud is extruded into strips with the diameter of about 7-10 cm by using an extruder, the strips are cut into blocks and put into a pan ball machine to be mixed with pulverized powder of coal slag, wood chips and the like to form balls, and the balls approximately contain 100 parts of wet red mud, 5 parts of coal slag powder, 1 part of wood chips, and the balance of about 65 parts of loose coal slag powder and 7 parts of wood chips. The mixture is conveyed to a storage yard for airing. After 1 week, the red mud blocks are raked out after losing plasticity, the surface is wetted by spraying lime water, and the weight of the lime water is about 2 percent of that of the red mud blocks, namely 2:100. And the rest of the coal slag powder and the saw dust which are not adhered to the red mud lumps are recycled.
After continuously placing for 2 weeks, forming higher strength, and then loading and carrying.
Sand, coal slag and stabilized domestic sludge are mixed into sandy loam in advance before a typhoon season (summer), and then according to the proportion of the sandy loam: the weight ratio of the embedded red mud blocks is 100: 50, planting peanuts and hot peppers on the ridges, planting sea horse teeth around the ridges, finding that the sea horse teeth are obviously diffused after 3 months, the peanuts and the hot peppers obviously grow and bear fruits, and preventing the ridges from being obviously damaged by typhoon and rainwater. Showing a remarkable resistance to water erosion.
Example 2:
red mud from detergent factory in Fujian Shishi is neutralized with waste pickling liquid. The product is yellow brown high viscosity mud, has water content of more than 60%, and is difficult to transport and dispose.
The neutralized red mud is extruded into strips with the diameter of about 5-6 cm by using an extruder, the strips are cut into blocks and put into a briquetting machine to be mixed with pulverized powder of coal slag, wood chips and the like for briquetting, and the prepared green body approximately contains 100 parts of wet red mud, 6 parts of coal slag powder, 1 part of wood chips, and the balance of loose coal slag powder and 8 parts of wood chips. The mixture is conveyed to a storage yard for airing. After 3 days, the red mud blocks are raked out after losing plasticity, lime water is sprayed to wet the surface, and the weight of the lime water is about 3 percent of that of the dry lime blocks, namely 3:100. And the rest of the coal slag powder and the saw dust which are not adhered to the red mud lumps are recycled.
After continuously placing for 2 weeks, forming higher strength, and then loading and carrying.
Mixing local sand, pulverized coal slag, shell fragments and stabilized activated sludge in the seaside sandy land in advance to obtain sandy loam, and mixing the sandy loam: the weight ratio of the embedded red mud blocks is 100: 60, the mixture of the proportion is piled up high and is ridged, and a large amount of embedded red mud block masses are additionally put on the windward side of the ridge to form a wind-shielding surface (similar to a wind-shielding wall), so that the sandy loam as a whole is formed: the weight ratio of the embedded red mud block mass is as high as 100: 200. Medlar seedlings and seaside evening primrose are planted on and around the ridges, after 6 months, the two plants are found to grow well, the seaside evening primrose blooms, the soil ridges can resist wind erosion of a seaside air port, the protective ridges have no obvious damage phenomenon, but have external wind and sand accumulation behaviors. Shows good wind-proof and sand-fixing ability. Compared with the contrast land which uses the stone blocks to shield the wind for the land and cover the land to reduce the steam evaporation, the plant growth vigor is optimized, and the plant growth vigor is related to the red mud embedding blocks which have stronger capacities of capturing dew and storing water vapor.
The process solves the problem of extremely difficult drying of the red mud by increasing the specific surface area of the red mud lumps and the water absorption of the barren materials, also solves the problem of dust during transportation and transportation of the dried red mud, and can realize large-scale resource optimization. In a word, the invention has high drying efficiency, low operation cost and good economic and environmental benefits.
Although specific embodiments of the invention have been described above, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, and that equivalent modifications and variations can be made by those skilled in the art without departing from the spirit of the invention, which is to be limited only by the appended claims.
Claims (7)
1. An environment-friendly treatment process of red mud is characterized in that: the process comprises the following steps:
extruding the neutralized wet red mud, cutting into segments, mixing at least one of mineral fiber and plant debris and barren powder with volcanic ash property with the mixed powder to form red mud blocks or pressed blanks, and using the redundant mixed powder which is not adhered to the red mud blocks as a powder bed for drying;
secondly, when the red mud block mass is dried to lose plasticity, raking out and embedding, namely mixing at least one of lime, calcium silicate cement and carbide slag with the red mud block mass, and performing volcanic ash reaction on barren powder with volcanic ash property and calcium ions under alkalinity to gradually convert the barren powder into volcanic ash cement materials to embed red mud blocks;
loosening and mixing sandy loam and the embedded red mud clusters to obtain the seaside greening soil material;
the sandy loam is prepared by premixing sand, coal cinder and clay doped with stabilized domestic sludge.
2. The environment-friendly treatment process of red mud according to claim 1, which is characterized in that: the neutralized wet red mud in the step one is the red mud neutralized by the pickling waste liquid.
3. The environment-friendly treatment process of red mud according to claim 1, which is characterized in that: the weight ratio of each component in the first step is as follows: neutralized wet red mud: barren powder with pozzolanic properties: at least one of the mineral fiber and the plant debris is 100: 10-300: 1-10.
4. The environment-friendly treatment process of red mud according to claim 1 or 3, characterized in that: the barren powder with volcanic ash property is at least one of fly ash, coal slag ash and steel slag ash.
5. The environment-friendly treatment process of red mud according to claim 1, which is characterized in that: and in the second step, the weight ratio of the red mud agglomerate to at least one of lime, calcium silicate cement and carbide slag is 100: 2-8.
6. The environment-friendly treatment process of red mud according to claim 1, which is characterized in that: the weight ratio of the sandy loam to the embedded red mud clusters in the third step is 100: 30-600.
7. The environment-friendly treatment process of red mud according to claim 1, which is characterized in that: the mineral fiber in the first step is at least one of peat scraps or rock wool and glass fiber, and the plant scraps are at least one of grass sawdust, waste paper pulp or paper sludge.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510895329.3A CN105481538B (en) | 2015-12-08 | 2015-12-08 | Environment-friendly treatment process for red mud |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510895329.3A CN105481538B (en) | 2015-12-08 | 2015-12-08 | Environment-friendly treatment process for red mud |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105481538A CN105481538A (en) | 2016-04-13 |
| CN105481538B true CN105481538B (en) | 2020-02-18 |
Family
ID=55668863
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510895329.3A Active CN105481538B (en) | 2015-12-08 | 2015-12-08 | Environment-friendly treatment process for red mud |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105481538B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113303198A (en) * | 2021-06-25 | 2021-08-27 | 湖北声荣再生资源利用有限公司 | Culture medium and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1673129A (en) * | 2005-02-06 | 2005-09-28 | 中国铝业股份有限公司 | Bayer process red mud matrix improvement technology |
| CN103193383A (en) * | 2013-04-03 | 2013-07-10 | 张勇 | Process method for producing inorganic fibers by using red mud |
| CN104446213A (en) * | 2014-12-10 | 2015-03-25 | 广西启利新材料科技股份有限公司 | Grouting material employing red mud as raw material |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103242101B (en) * | 2013-05-21 | 2014-09-10 | 湖南农业大学 | Red-mud-based nitrogen phosphorus controlled release agent and preparation method thereof |
| CN104119161B (en) * | 2014-08-12 | 2015-12-30 | 许盛英 | The production method of red mud compression Nutrition Soil |
-
2015
- 2015-12-08 CN CN201510895329.3A patent/CN105481538B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1673129A (en) * | 2005-02-06 | 2005-09-28 | 中国铝业股份有限公司 | Bayer process red mud matrix improvement technology |
| CN103193383A (en) * | 2013-04-03 | 2013-07-10 | 张勇 | Process method for producing inorganic fibers by using red mud |
| CN104446213A (en) * | 2014-12-10 | 2015-03-25 | 广西启利新材料科技股份有限公司 | Grouting material employing red mud as raw material |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105481538A (en) | 2016-04-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104909816B (en) | A kind of sintering grow type super light ceramisite produced with mud and its manufacture method | |
| CN101054280B (en) | Plant fiber enhanced color clinker solid brick and preparation method thereof | |
| CN107021778B (en) | Plant-growing pervious concrete system for realizing sludge recycling treatment and preparation method thereof | |
| CN102795831B (en) | Deep foundation pit soil-sintered porous brick and production method thereof | |
| CN102161579A (en) | Burning-and-steam-curing-free alkaline slag brick and preparation method thereof | |
| CN104310813B (en) | Green ecological cement with waste material of stone as raw material and production method thereof | |
| CN106278088A (en) | A kind of environmental protection is non-burning brick and preparation method thereof | |
| CN107488019A (en) | A kind of non-sintered gold tailings brick and its preparation technology | |
| CN111485940A (en) | Method for backfilling and reclaiming mining pits by using slime and red mud generated by bauxite ore dressing and smelting | |
| CN111018418B (en) | Method for recycling waste phosphorite on site | |
| CN103332924A (en) | Preparation method of sintered water permeable brick | |
| CN101343149B (en) | Sewage water body refuse type cement and method of preparing the same | |
| CN104016601A (en) | Method for producing cement cementing material through industrial waste residue sludge | |
| CN102745961A (en) | Mine mullock pervious concrete and preparation method thereof | |
| CN114213071A (en) | Method for preparing baking-free bricks by using building residue soil | |
| CN101182162A (en) | Small-size concrete hollow block using shell and waste ash slag as raw material | |
| CN102167539B (en) | Masonry mortar plasticizer and preparation method thereof | |
| CN105481538B (en) | Environment-friendly treatment process for red mud | |
| CN102815880B (en) | A kind of technique utilizing saponified residue brickmaking | |
| CN114085054B (en) | Method for preparing functional water permeable material by using multi-source solid waste | |
| CN105367041A (en) | Abrasion-resistant and anti-fracturing sintered water-permeable floor tile | |
| CN102276222B (en) | Phosphogypsum wall brick and preparation method thereof | |
| CN105837144A (en) | Non-bearing deposited-silt autoclaved sand-lime brick and preparation method thereof | |
| CN112242182A (en) | Reverse design method, preparation method and application of recycled lightweight concrete | |
| Han et al. | Comprehensive Utilization of Fly Ash |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |