Machine-made sand and application thereof

Abstract

The invention particularly relates to machine-made sand and an application thereof, and belongs to the fields of building material processing technology and environmental protection. The machine-madesand is prepared through the following steps: step 1, after high-temperature liquid ferronickel slag melt is discharged from a slag opening of a furnace, slow cooling air quenching cooling is carriedout on the high-temperature liquid ferronickel slag melt, and ferronickel slag is obtained; and during slow cold air quenching cooling, the cooling speed is controlled to be smaller than or equal to 70 DEG C / s; step 2, the ferronickel slag is placed in a jaw crusher and is subjected to primary crushing; and step 3, the ferronickel slag obtained in the step 2 is placed in an efficient fine crusherand is subjected to fine crushing, so that the ferronickel slag machine-made sand is obtained. After optimization, the measurement result of the crushing index value of the obtained machine-made sandis 6.8-7%. The machine-made sand provided by the invention is mixed with natural sand to be used as a building material. By means of a series of treatment, especially air cooling treatment at a reasonable speed, on the ferronickel slag, the ferronickel slag has excellent performance, and necessary conditions are provided for replacing a part of concrete fine aggregate and changing waste into valuable resources for cyclic utilization.

Description

technical field [0001] The invention relates to a method for comprehensive utilization of ferronickel slag resources, in particular to machine-made sand and its application, and belongs to the fields of building material processing technology and environmental protection. Background technique [0002] In the process of concrete preparation, natural sand or rock-made sand are mainly used as aggregates at present, but there are some problems when using these as aggregates. Sand is a non-renewable resource. Excessive mining will cause huge damage to the river environment. Under the premise that the mining of river sand is prohibited, some processes choose to use ore grinding to prepare machine-made sand. The mining + grinding process will not only consume a lot of energy. At the same time, it also destroys the mountain environment; the discharge of ferronickel slag increases year by year with the gradual expansion of the scale of smelting nickel-iron alloy in my country. In rece...

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Problems solved by technology

[0004] In terms of technology, the treatment of nickel-iron slag mostly adopts the water quenching method. The high-temperature liquid nickel-iron slag melt is discharged from the slag outlet of the furnace and directly enters the water for water quenching. Due to the fast cooling speed of water quenching, a large amount of glass phase will be produced, which is used for concrete At the same time, active silica can react with calcium hydroxide in the pores of hardened cement paste to generate secondary hydration products, causing the volume of concrete to expand and destroy the concrete structure; in addition, the material in the glass state is not high in strength and high in brittleness. If the crystallinity of the slag is too low, the ferronickel sand produced does not meet the requirements for the firm crushing value of the machine-made sand in the "Building Sand" (GB / T14684-2011) standard

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