Nickel iron slag make sand and configure concrete

Date: Jul. 02, 2021

As a natural resource, river sand is an important raw material for the preparation of concrete and mortar. In recent years, many places have faced a shortage of natural sand resources and a decline in quality. Because river sand mining has caused serious damage to the river bed and the surrounding natural environment, mining of some river sand resources is prohibited or restricted. Rigid demand in the market and resource Under the dual influence of increasing shortages, the price of river sand keeps rising. Nickel-iron slag is an industrial waste slag produced in the process of smelting nickel-iron alloys. At present, the amount of nickel-iron slag produced is increasing year by year. Nickel-iron slag has a dense structure, poor grindability, and high energy consumption when used as a cementitious material. The comprehensive utilization rate of nickel-iron slag is low, and most of them are stored in the open air or landfilled. This not only wastes resources, takes up a lot of land, but also destroys the surrounding ecological environment. This article studies the use of nickel-iron slag to partially replace river sand and configure mortar feasibility.

(1) Put the nickel-iron slag in a small test mill to crush, and divide the crushed sample into 4.75~2.36mm, 2.36~1.18mm, 1.18~0.60mm, using a square-hole sieve, There are seven grades below 0.60～0.30mm, 0.30～0.15mm, 0.15～0.075mm and 0.075mm, which are matched into nickel-iron slag sand according to the gradation of river sand.

(2) Replace the river sand with the prepared nickel-iron slag sand according to 0, 20%, 40%, 60%, 80%, and 100%, and prepare the mortar according to the ratio shown in Table 3, and study the replacement of the nickel-iron slag sand The influence of the amount on the strength, delamination, consistency, bonding performance, volume stability and other properties of the mortar.

With the increase in the amount of nickel iron slag sand replaced, the viscosity first increases and then decreases, and the stratification first decreases and then increases; and when the slag sand replacement amount is greater than 40%, the mortar will have bleeding; after 60% replacement, the appearance of the mortar There is a grainy feeling, the greater the amount of substitution, the worse the surface smoothness.

A proper amount of river sand can make up for the defects of the bad shape of the nickel-iron slag sand, so after part of the nickel-iron slag sand replaces the river sand, the strength of the mortar increases. In addition, the angular structure of the surface of the crushed nickel-iron slag can enable effective mechanical engagement between the aggregates, and can also increase the strength of the mortar.