Mechanism of Alkali‐Activated Copper‐Nickel Slag Material

Abstract

A copper-nickel slag-based alkali-activated cementing material (CNSCM) for backfilling was prepared using copper-nickel slag as a raw material and sodium silicate (SS) as an activating agent. The effects of SS content (6%, 8%, and 10%) and curing humidity on the compressive strength of CNSCM were investigated using an electronic universal testing machine. Types of hydration products and microstructures were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results indicated that by increasing the SS content, the compressive strength of the CNSCM exhibited an increasing trend, followed by a decreasing trend. The optimal content was 8%. Humidity was identified as another factor affecting compressive strength, which reached 17 MPa after curing for 28 d under standard conditions. A decrease in humidity could improve the compressive strength of the material. The main hydration reaction products of the CNSCM were C-S-H gel, Fe (OH)2 or Fe (OH)3 gel, and CaCO3.

Influence of Blend Ratio on Compressive Strength of Soda Ash Activated Fly Ash and Copper Slag Pastes

“…NaOH activators resulted in the fastest product structural build-up. [15] investigated the influence of parameters such as activator dosage, curing condition, and curing age on microstructural as well as strength development of alkali-activated copper-nickel slag. Optimum Na 2 SiO 3 dosage was 8% for compressive strength of 17 MPa at 28 days.…”

Fineness Effect on Pozzolanic Activity of Cu‐Ni Slag in Cemented Tailing Backfill

“…is indicated that more CH is detected in CP sample, which means the CH in CP-10, CP-30, and CP-50 samples was consumed by the pozzolanic reaction of the Cu-Ni slag. e reaction of pozzolanic materials is generally that the active parts SiO 2 , Al 2 O 3 , and Ca(OH) 2 react with pozzolanic materials in the following form [10]:…”

“…e existing research [4][5][6] shows that the nonferrous smelting slag has certain pozzolanic activity or potential hydraulic property. Compared with the water-quenched blast furnace slag [7][8][9][10][11][12], the nonferrous smelting slag has the problem of the relatively low pozzolanic activity or potential hydraulic property, and the comprehensive utilization added value is low. erefore, the relevant research and application are relatively few, and the overall utilization rate is not high.…”

Effect of Sodium Aluminate Dosage as a Solid Alkaline Activator on the Properties of Alkali‐Activated Slag Paste

“…AAS had the characteristics of low-carbon dioxide emissions and recycling of industrial solid waste, and the advantages of its good early-phase mechanical properties, high-temperature resistance, and strong corrosion resistance had been proved by many studies [5]. However, the disadvantages of AAS were the too fast setting time, cumbersome preparation process, and alkali corrosive damage; these points restricted the AAS application and promotion.…”