阅读说明：本技术 一种机制砂及其应用 (Machine-made sand and application thereof ) 是由 周乐君 王万林 罗豪 吴厚发 颜雄 于 2019-10-22 设计创作，主要内容包括：本发明特别涉及一种机制砂及其应用；属于建筑材料加工技术和环境保护领域。所述机制砂通过下述步骤制备：步骤一高温液态镍铁渣熔体从炉子渣口排出后,对其进行缓冷风淬冷却,得到镍铁渣；缓冷风淬冷却时,控制冷却速度小于等于70℃/s；步骤二将镍铁渣置于颚式破碎机进行一级破碎,步骤三将步骤二所得镍铁渣再置于高效细碎机中进行细碎破碎,制得镍铁渣机制砂。优化后,本发明所得机制砂,其压碎性指标值的测量结果为6.8-7％。本发明所设计的机制砂与天然砂混合后,作为建材使用。本发明通过对镍铁渣的一系列处理、尤其是合理速度的风冷处理,使其具有优异的性能,为其代替一部分混凝土细集料,变废为宝资源循环利用提供了必要条件。(The invention especially relates to machine-made sand and application thereof; belongs to the field of building material processing technology and environmental protection. The machine-made sand is prepared by the following steps: step one, after a high-temperature liquid ferronickel slag melt is discharged from a slag hole of a furnace, carrying out slow cooling air quenching on the melt to obtain ferronickel slag; when the slow cooling air quenching is carried out, the cooling speed is controlled to be less than or equal to 70 ℃/s; and step two, placing the ferronickel slag in a jaw crusher for primary crushing, and placing the ferronickel slag obtained in the step three in a high-efficiency fine crusher for fine crushing to obtain the sand made by the ferronickel slag machine. After optimization, the measured result of the crushability index value of the machine-made sand obtained by the invention is 6.8-7%. The machine-made sand designed by the invention is mixed with natural sand and then used as building materials. The invention has excellent performance through a series of treatments to the nickel-iron slag, especially the air cooling treatment with reasonable speed, and provides necessary conditions for replacing a part of concrete fine aggregate and recycling waste resources.)

1. A machine-made sand characterized by; the machine-made sand is prepared by the following steps:

step one, after a high-temperature liquid ferronickel slag melt is discharged from a slag hole of a furnace, carrying out slow cooling air quenching on the melt to obtain ferronickel slag; when the slow cooling air quenching is carried out, the cooling speed is controlled to be less than or equal to 70 ℃/s;

step two

Putting the ferronickel slag into a jaw crusher for primary crushing,

step three

And D, placing the ferronickel slag obtained in the step two into a high-efficiency fine crusher for fine crushing to obtain ferronickel slag machine-made sand.

2. The manufactured sand of claim 1, wherein: in the first step, the nickel-iron slag is cooled by adopting an air quenching method to obtain a mineral phase with the crystallinity of 95-100%.

3. The machine-made sand according to claim 1, wherein the ferronickel slag is cooled in the first step by an air quenching method, so that sensible heat of the ferronickel slag can be recovered, and hot air at 300-400 ℃ is generated after heat exchange.

4. The manufactured sand of claim 1, wherein: and in the second step, a jaw crusher is adopted to crush the raw materials for one time, the maximum feeding granularity of the equipment is not more than 640mm, and the rotating speed of an eccentric shaft is 250-300 r/min.

5. The manufactured sand of claim 1, wherein: in the third step, the high-efficiency fine crusher is adopted to carry out secondary crushing on the raw materials, the maximum feeding granularity of the equipment is not more than 180mm, and the width of the discharge port is adjusted and controlled to be 5-10 mm.

6. The manufactured sand of claim 1, wherein: the radioactivity of the sand produced by the ferronickel slag machine meets the requirement that the internal irradiation index and the external irradiation index of a building main body material in the building material radionuclide limitation (GB 6566-2010) are both less than or equal to 1.0, and the leaching toxicity meets the requirement that no harmful influence is generated on human bodies, organisms and the environment in the building sand (GB/T14684-2011).

7. The manufactured sand of claim 1, wherein: after the ferronickel slag is prepared into the machine-made sand, according to a measuring method of the national standard 'building sand' (GB/T14684-2011), the particle grading of the ferronickel slag is in the grading standard of a machine-made sand 1 area, the fineness modulus is within the range of 3.7-3.1, and the ferronickel slag is coarse sand; robustness: mass loss is less than or equal to 8 percent, and the crushing performance index value is less than or equal to 20 percent; apparent density is more than or equal to 2500kg/m³(ii) a The loose bulk density is more than or equal to 1400kg/m³The porosity is less than or equal to 44 percent; MB value is less than or equal to 1.4, stone powder content: less than or equal to 10.0% by mass, content of mud lumps: is less than or equal to 1.0 percent by mass. In the harmful substances, the content of mica is less than or equal to 1.0 percent, the content of light substances is less than or equal to 1.0 percent, and the content of organic substances is qualified; according to SO₃Calculated by mass, the content of sulfide and sulfate is less than or equal to 0.5 percent; the content of chloride ions is less than or equal to 0.06 percent based on the mass of the chloride ions.

8. The manufactured sand of claim 7, wherein: the nickel-iron slag comprises the following components in percentage by mass: SiO 2₂：45-55％、MgO：25-35％、Fe₂O₃：7-13％、CaO：1-2％、Al₂O₃:4-8％。

9. The manufactured sand of claim 8, wherein: after the ferronickel slag is made into the machine-made sand, the measurement result of the crushing index value is 6.8-7% according to the measuring method of GB/T14684-2011 national standard 'building sand'.

10. Use of a machine-made sand according to any of claims 1-9, wherein: the machine-made sand is mixed with natural sand and then used as a building material.

Technical Field

The invention relates to a method for comprehensively utilizing ferronickel slag resources, in particular to machine-made sand and application thereof; belongs to the field of building material processing technology and environmental protection.

Background

In the concrete preparation process, natural sand or rock machine-made sand is mainly used as aggregate at present, but problems are caused when the natural sand or rock machine-made sand is used as the aggregate. The sand belongs to non-renewable resources, the river channel environment is greatly damaged by excessive mining, and under the premise that the river sand is forbidden to be mined, an ore grinding and preparing machine is adopted to prepare the sand in part of processes, so that a large amount of energy is consumed in the mining and grinding processes, and the mountain environment is also damaged; the discharge amount of the nickel-iron slag is gradually increased year by year along with the gradual expansion of the scale of smelting the nickel-iron alloy in China, and in recent years, the discharge amount of the nickel-iron slag in China becomes the fourth most smelting slag after iron slag, steel slag and red mud.

The ferronickel slag is waste slag generated in the process of smelting ferronickel alloy from the nickel iron ore, and has the problems of low utilization rate, land occupation by a large amount of stockpiling and influence on the surrounding environment at present. The nickel-iron slag can be divided into blast furnace nickel-iron slag and electric furnace nickel-iron slag, China mainly takes the electric furnace nickel-iron slag as a main material, and invar red et al propose a method for preparing sand by using a composite nickel slag preparation machine in 'a nickel slag composite sand and a preparation method thereof', but the crushing index of the machine-made sand obtained by the method is more than 20%, and only meets the II-type standard in 'building sand' (GB/T14684-2011).

In the process, a water quenching method is mostly adopted for treating the nickel-iron slag, a high-temperature liquid nickel-iron slag melt is discharged from a slag port of a furnace and directly enters water for water quenching, a large amount of glass phases can be generated due to the rapid water quenching speed, and when the activated silicon oxide is used as concrete, the activated silicon oxide can react with calcium hydroxide in pores of hardened cement slurry to generate secondary hydration products, so that the volume of the concrete is expanded, and a concrete structure is damaged; in addition, the glass-state substance has low strength and high brittleness, and if the crystallinity of the slag is too low, the prepared ferronickel sand does not meet the requirement of the machine-made sand firmness crushing value in the building sand (GB/T14684-2011) standard.

Therefore, the invention selects the air quenching method to prepare the sand by the ferronickel slag preparation machine, and the ferronickel is cooled by airThe cooling crystallization phase component is magnesium orthosilicate (Mg)₂SiO₄) And magnesium metasilicate (MgSiO)₃) The prepared product has high strength, and the magnesium oxide enters a crystalline phase to cause the activity of the magnesium oxide to be low, so that the magnesium oxide is used for replacing a part of river sand or rock machine-made sand as concrete aggregate, thereby changing waste into valuable and achieving the purpose of recycling resources.

Disclosure of Invention

Aiming at the problems, the invention provides a brand-new method for preparing sand by a ferronickel slag preparation machine, belonging to the technical field of building material processing and the field of environmental protection.

The invention relates to machine-made sand which is prepared by the following steps:

step one, after a high-temperature liquid ferronickel slag melt is discharged from a slag hole of a furnace, carrying out slow cooling air quenching on the melt to obtain ferronickel slag; when the slow cooling air quenching is carried out, the cooling speed is controlled to be less than or equal to 70 ℃/s, preferably 30-60 ℃/s, and more preferably 30-35 ℃/s;

step two

Putting the ferronickel slag into a jaw crusher for primary crushing,

step three

And D, placing the ferronickel slag obtained in the step two into a high-efficiency fine crusher for fine crushing to obtain ferronickel slag machine-made sand.

The invention relates to machine-made sand, wherein in the first step, nickel-iron slag is cooled by adopting an air quenching method to obtain a mineral phase with the crystallinity of 95-100%. The crystalline phase component is magnesium orthosilicate (Mg)₂SiO₄) And magnesium metasilicate (MgSiO)₃)。

According to the machine-made sand, the nickel-iron slag is cooled by adopting an air quenching method in the step one, so that the sensible heat of the nickel-iron slag can be recovered, and hot air at the temperature of 300-400 ℃ is generated after heat exchange.

In the step two, the raw materials are crushed for the first time by adopting a jaw crusher, the maximum feeding granularity of the equipment is not more than 640mm, and the rotating speed of an eccentric shaft is 250-300 r/min.

In the third step of the machine-made sand, the raw materials are secondarily crushed by using a high-efficiency fine crusher, the maximum feeding granularity of the machine-made sand is not more than 180mm, and the width of a discharge hole is adjusted and controlled to be 5-10 mm.

The radioactivity of the sand made by the ferronickel slag machine meets the requirement that the internal irradiation index and the external irradiation index of a building main body material in the building material radionuclide limitation (GB 6566-2010) are both less than or equal to 1.0, and the leaching toxicity meets the requirement that no harmful influence is generated on human bodies, organisms and the environment in the building sand (GB/T14684-2011).

According to the invention, after ferronickel slag is prepared into the machine-made sand, according to a measuring method of 'building sand' (GB/T14684-2011) of a national standard, the particle grading of the ferronickel slag is in a grading standard of a machine-made sand 1 area, and the ferronickel slag is coarse sand with a fineness modulus of 3.7-3.1; robustness: mass loss is less than or equal to 8 percent, and the crushing performance index value is less than or equal to 20 percent; apparent density is more than or equal to 2500kg/m³(ii) a The loose bulk density is more than or equal to 1400kg/m³The porosity is less than or equal to 44 percent; MB value is less than or equal to 1.4, stone powder content: less than or equal to 10.0% by mass, content of mud lumps: is less than or equal to 1.0 percent by mass. In the harmful substances, the content of mica is less than or equal to 1.0 percent, the content of light substances is less than or equal to 1.0 percent, and the content of organic substances is qualified; according to SO₃Calculated by mass, the content of sulfide and sulfate is less than or equal to 0.5 percent; the content of chloride ions is less than or equal to 0.06 percent based on the mass of the chloride ions.

According to a preferable scheme, the machine-made sand comprises the following components in percentage by mass: SiO 2₂：45-55％、MgO：25-35％、Fe₂O₃：7-13％、CaO：1-2％、Al₂O₃:4-8％。

As a further preferable scheme, after the ferronickel slag is prepared into the machine-made sand, the measurement result of the crushing performance index value is 6.8-7% according to the measuring method of GB/T14684-2011 national standard 'building sand'.

The machine-made sand is mixed with natural sand and then used as a building material. As a further preferable scheme, the fineness modulus of the natural sand is 3.5-3.2. As a further preferable scheme, the mass ratio of the machine-made sand to the natural sand is 25-35%: 45 to 75 percent.

The principle of the invention is as follows:

the sandstone aggregate plays a skeleton role in concrete, such as the functions of transferring stress, restraining shrinkage, preventing cracking and the like, the water-quenched ferronickel slag can generate a large amount of glass phase, and from the thermodynamic perspective, a glassy substance has larger internal energy than a corresponding crystalline substance, so that the glassy substance always has the tendency of reducing the transformation from the internal energy to the crystalline state, therefore, the glass is metastable in general, the glass state substance strength is not high, and the crushing value of the nickel-iron slag in the standard can not be met, the method of the invention adopts an air cooling mode to cool the nickel-iron slag, the crystal phase components generated by the air-cooled nickel-iron slag are magnesium orthosilicate and magnesium metasilicate, so that the ferronickel slag produced by the method can be used as fine aggregate to be added into concrete, the matching work of primary crushing and fine crushing is adopted, so that the produced ferronickel slag can meet the requirements of particle size distribution and fineness modulus.

Compared with the original ferronickel slag treatment mode, the method has the following advantages:

1) the cooling process of the ferronickel slag does not need to consume water resources, the whole process is simple, energy is saved, the environment is protected, and hot air can be reused.

2) Compared with water-quenched slag, the ferronickel slag is hard in texture and stable in performance, and can improve the compressive strength of concrete when used for the concrete.

The specific implementation mode is as follows:

the invention is further illustrated by the following examples, which are intended to be illustrative only and are not intended to be in any way limiting.