阅读说明：本技术 一种机制砂尾料的处理方法及利用该机制砂尾料制备的混凝土 (Processing method of machine-made sand tailings and concrete prepared by utilizing machine-made sand tailings ) 是由 *** 何建乔 韩玉 池浩 翁怡令 凌忠 冯春萌 袁征 李威 李彩霞 黄建斌 于 2019-12-05 设计创作，主要内容包括：本发明涉及建筑材料领域,特别涉及机制砂尾料的处理方法及利用该机制砂尾料制备的混凝土。本发明的混凝土由以下重量份的原料组成：水泥250-400份,机制砂尾料15-90份,粉煤灰0-90份,机制砂700-1000份,碎石900-1200份,水140-220份和减水剂4-10份。本发明选用机制砂生产“废料”作为新型矿物掺合料应用于混凝土中,可降低施工成本,同时可以满足混凝土各项指标要求,且具有优异的工作性能和均匀的外观质量,明显优于传统混凝土。机制砂尾料在混凝土中的应用实现了废固物再利用,“变废为宝”、绿色节能环保的目的。(The invention relates to the field of building materials, in particular to a method for treating machine-made sand tailings and concrete prepared by using the machine-made sand tailings. The concrete of the invention is composed of the following raw materials in parts by weight: 400 portions of cement 250-containing materials, 15-90 portions of machine-made sand tailings, 0-90 portions of fly ash, 1000 portions of machine-made sand 700-containing materials, 1200 portions of broken stone 900-containing materials, 220 portions of water 140-containing materials and 4-10 portions of water reducing agents. The invention selects the 'waste material' produced by the machine-made sand as the novel mineral admixture to be applied to the concrete, can reduce the construction cost, can meet the requirements of various indexes of the concrete, has excellent working performance and uniform appearance quality, and is obviously superior to the traditional concrete. The application of the machine-made sand tailings in the concrete realizes the purposes of recycling waste solids, changing waste into valuable, saving energy and protecting environment.)

1. A treatment method of machine-made sand tailings is characterized by comprising the following steps:

(1) collecting the machine-made sand tailings, and drying the collected machine-made sand tailings by powder separation or hot air so that the water content of the machine-made sand tailings is lower than 1%;

(2) and putting the dried machine-made sand tailings into a crusher for crushing, and then grinding and processing the machine-made sand tailings until the particle size is 325-600 meshes and the fineness is not more than 10%.

2. The method as claimed in claim 1, wherein the step (2) comprises grinding the machine-made sand tailings to a particle size of 400-500 meshes and a fineness of 6%.

3. The method of claim 1, wherein the machine-made sand tailings are solid waste generated in a machine-made sand production process, the machine-made sand tailings contain calcium carbonate more than 75%, and methylene blue value is not more than 1%.

4. The concrete is characterized in that the machine-made sand tailings obtained by the treatment method of any one of claims 1 to 3 are used as raw materials, and the concrete is specifically composed of the following raw materials in parts by weight: 400 portions of cement 250-containing materials, 15-90 portions of machine-made sand tailings, 0-90 portions of fly ash, 1000 portions of machine-made sand 700-containing materials, 1200 portions of broken stone 900-containing materials, 220 portions of water 140-containing materials and 4-10 portions of water reducing agents.

5. The concrete according to claim 4, wherein the concrete is prepared from the following raw materials in parts by weight: 333 parts of cement, 32 parts of fly ash, 32 parts of machine-made sand tailings, 825 parts of machine-made sand, 1010 parts of broken stone, 170 parts of water and 5.2 parts of a water reducing agent.

6. The concrete according to claim 4, wherein the modulus of fineness of the machine-made sand is 2.6-3.0, the mud content is less than 1.0%, the mud cake content is less than 0.5%, the MB value is less than 1.0, and the stone powder content is 8-10%.

7. The concrete according to claim 4, wherein the fly ash is class I fly ash or class II fly ash.

8. The concrete of claim 4, wherein the water reducing agent is one of a polycarboxylic acid water reducing agent, a naphthalene water reducing agent or an amino water reducing agent or any combination thereof.

9. A concrete according to claim 4 wherein the macadam is a continuous graded macadam having a particle size of from 5 to 30mm and having a void content of less than 40%, a crush value index of not more than 7% and a pin-flaked particle content of not more than 5%.

10. A concrete according to claims 4-9, wherein said concrete is prepared by the following method:

1) mixing the machine-made sand tailing, cement, fly ash, machine-made sand and broken stone, and stirring for 10-30s to obtain a material A;

2) mixing and stirring water and the water reducing agent uniformly, then mixing the mixture with the material A obtained in the step 1), and stirring the mixture for 120-180 seconds to obtain the concrete.

[ technical field ] A method for producing a semiconductor device

The invention relates to the field of building materials, in particular to a method for treating machine-made sand tailings and concrete prepared by using the machine-made sand tailings.

[ background of the invention ]

The natural sand is a non-renewable local resource, and along with the increasing expansion of the national basic construction scale and the gradual enhancement of the protection measures of the farmland and river channel environment, the use of the natural sand resource is limited. The excessive exploitation of natural sand for decades brings destructive damage to river channels, seriously affects the stability of riverbeds and the flood control safety, and the natural sand resources are greatly reduced at present and are nearly exhausted, so that the contradiction between the supply and demand of concrete sand is particularly prominent. According to incomplete statistics, the use of the machine-made sand in concrete is gradually increased, the usage amount of the sand in China is increased year by year since 2008, the total usage amount of sand aggregate is over 200 hundred million tons, the proportion of the machine-made sand usage amount to the total usage amount of the sand is also increased year by year, the machine-made sand usage amount is over 180 hundred million tons, and the proportion is close to 90 percent. It is expected that after 3-5 years, the machine-made sand will completely replace the natural sand.

A large amount of tailings are inevitably generated in the production process of the machine-made sand, the production rate of the current sand making equipment is between 15% and 35%, and not less than 40 hundred million tons of tailings are generated nationwide every year. Roadbed backfill, cement blending and other methods can only consume about 50 percent, stacking and burying are still the most main treatment modes, ecological restoration of cultivated land and forest land is seriously affected, and the problems of environmental pollution and resource waste of machine-made sand tailings are very serious.

[ summary of the invention ]

In view of the above, the invention aims to select the machine-made sand production waste material as a novel mineral admixture to be applied to concrete, so that the construction cost can be reduced, and meanwhile, various index requirements of the concrete can be met.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a treatment method of machine-made sand tailings comprises the following steps:

(1) collecting the machine-made sand tailings, and drying the collected machine-made sand tailings by powder separation or hot air so that the water content of the machine-made sand tailings is lower than 1%;

(2) putting the dried machine-made sand tailings into a crusher for crushing, and then grinding and processing the machine-made sand tailings until the particle size is 325-600 meshes and the fineness is not more than 10 percent; the grinding process of the machine-made sand tailings adopts a Raymond grinding production line.

In the invention, further, in the step (2), the machine-made sand tailings are ground and processed to have the particle size of 400-500 meshes and the fineness of 6%.

In the invention, further, the machine-made sand tailings are solid wastes formed in the production process of machine-made sand, the calcium carbonate content of the machine-made sand tailings is more than 75%, the methylene blue value is not more than 1%, and the specific surface area is 600m²/kg。

The application also provides concrete, which adopts the machine-made sand tailings obtained by the treatment method as a raw material, and the concrete is specifically composed of the following raw materials in parts by weight: 400 portions of cement 250-containing materials, 15-90 portions of machine-made sand tailings, 0-90 portions of fly ash, 1000 portions of machine-made sand 700-containing materials, 1200 portions of broken stone 900-containing materials, 220 portions of water 140-containing materials and 4-10 portions of water reducing agents. The cement is Portland cement produced by Huarun cement.

In the invention, further, the concrete is composed of the following raw materials in parts by weight: 333 parts of cement, 32 parts of fly ash, 32 parts of machine-made sand tailings, 825 parts of machine-made sand, 1010 parts of broken stone, 170 parts of water and 5.2 parts of a water reducing agent.

In the invention, furthermore, the fineness modulus of the machine-made sand is 2.6-3.0, the mud content is less than 1.0%, the mud block content is less than 0.5%, the MB value is less than 1.0, and the stone powder content is 8-10%.

In the invention, further, the fly ash is grade I fly ash or grade II fly ash.

In the invention, the water reducing agent is one or any combination of a polycarboxylic acid water reducing agent, a naphthalene water reducing agent or an amino water reducing agent.

In the invention, the water reducing agent is preferably a polycarboxylic acid water reducing agent with a water reducing rate of more than 25% and a solid content of more than 30%.

In the invention, the macadam is a continuous graded macadam with the grain diameter of 5-30mm, the void ratio is less than 40%, the crushing value index is not more than 7%, and the content of needle-shaped particles is not more than 5%.

In the invention, further, the concrete is prepared by the following method:

1) mixing the machine-made sand tailing, cement, fly ash, machine-made sand and broken stone, and stirring for 10-30s to obtain a material A;

2) mixing and stirring water and the water reducing agent uniformly, then mixing the mixture with the material A obtained in the step 1), and stirring the mixture for 120-180 seconds to obtain the concrete.

In the present invention, the stirring time in step 1) is preferably 15s, and the stirring time in step 2) is preferably 120 s.

At present, most of the treatment modes of the machine-made sand tailings are landfill, so that the machine-made sand tailings not only cause harm to the environment, but also waste resources, but because the machine-made sand tailings are waste materials, the performance of the machine-made sand tailings in all aspects can hardly meet the index requirements of concrete; the applicant selects the machine-made sand tailings with the calcium carbonate content of more than 75 percent to carry out a series of treatments to obtain the machine-made sand tailings with the particle size of 400-plus 500 meshes and the fineness of 6 percent, and tests prove that the machine-made sand tailings have the effects of improving the grading of aggregate particles and increasing the degree of compactness in concrete by the filling effect; in the cement hydration reaction process, the machine-made sand tailings are adsorbed on the surface of cement to generate calcium ions, so that calcium oxide is prevented from locally growing into large crystals, and cement hydration is promoted to a certain extent; moreover, the specific surface area is 600m²Research shows that the hydration of cement can be effectively promoted under the specific surface area, and the strength requirement of concrete is met, at the moment, calcium carbonate in the machine-made sand tailing reacts with aluminate in the cement to generate hydrated calcium carbonate aluminate with certain strength. The applicant finds that the machine-made sand tailings treated by the method have the characteristics of small fineness, easy agglomeration when meeting water and the like, so that the smaller the fineness of the machine-made sand tailings is, the better the fineness is, and researches find that the performances of the concrete obtained by adopting 250-mesh groups and the concrete obtained by adopting 800-mesh groups are not the same as those of the concrete obtained by the fineness limited by the method, so that the optimal mesh number is determined to be 400-500 meshes; in addition, the applicant has also found that the machine-made sand tailings are not uniformly dispersed when directly stirred with water, resulting in poor flow properties of concrete mixtures, while affecting the sameHydration reaction of cement results in the reduction of mechanical performance of concrete. Comparing the seventh group and the twelfth group, it was found that even increasing the stirring time in the preparation method of the twelfth group could not alleviate the problem of dispersion of the machine-made sand tailings. The flowing property and the strength of the concrete can be effectively improved by comprehensively judging the machine-made sand tailings, but the particle size, the treatment process for preparing the concrete and the like all influence the performance of the concrete.

The invention has the following beneficial effects:

according to the invention, the solid waste in the production process of the machine-made sand, namely the machine-made sand tailing, is selected and used in concrete as a novel mineral admixture after being treated, so that the long-term working performance of a concrete mixture is improved and the appearance quality of the concrete is improved while various technical requirements of the specification are met, and the machine-made sand tailing can be greatly digested, so that the problem that the machine-made sand tailing pollutes the environment is solved, the waste solid is recycled, the dependence of the concrete on mineral admixtures such as fly ash is reduced, the concrete cost is reduced, and the concrete quality is improved; the method solves the problems, the applicant also researches the working performance, the mechanical property and the like of the concrete, improves the construction performance of the concrete by optimizing raw material components, preparation parameters and the like, and the machine-made sand tailing concrete prepared by the formula and the method has stable working performance, excellent mechanical property and uniform appearance quality.

[ description of the drawings ]

FIG. 1 is a diagram showing the appearance of concrete of a first group in a test example;

FIG. 2 is a view showing the appearance of the concrete of the fourth group in the test examples.

[ detailed description ] embodiments

The invention is further illustrated below with reference to the figures and examples and tests.