Combined Recycling of White Rice Husk Ash as Cement Replacement and Metal Furnace Slag as Coarse-Aggregate Replacement to Produce Self-Consolidating Concrete

According to empirical evidence,high levels of energy and considerable amounts of natural resources are used in the production of concrete.Given the context,this study explores self-consolidating concrete(SCC)that includes rice husk ash(RHA)and metal furnace slag(MFS)as an alternative to cement and the natural aggregates in standard SCC mixes.In this study,mixture designs are investigated with 20 wt.%of RHA,10–30 wt.%of MFS and water-to-powder material ratios of 0.30 and 0.40.Based on the findings regarding the fresh-state,hardened-state,and durability properties of the resulting SCC mixes,it is evident that the use of RHA and MFS can significantly improve the properties of concrete.The highest compressive strength was achieved for SCC with 20 wt.%RHA and 10 wt.%MFS.This outcome should be used as a basis for further investigations into the production of concrete materials that are both high-performance and sustainable.

Suggestions on Refractories in Nonferrous Metal Smelting Furnaces/Kilns

This paper introduces the refractories used in various nonferrous metal smelting equipment in China and the existing problems, and puts forward suggestions on the material of refractories, application of new technologies and production management of refractories, etc.

Dephosphorization stability of hot metal by double slag operation in basic oxygen furnace

Double slag process was adopted to produce low-phosphorus steel from middle-phosphorus hot metal.To achieve a stable dephosphorization operation,conventional process was modified as follows：the blowing time was extended by approximately 1min by reducing the oxygen supply flow rate;calcium ferrite pellets were added to adjust the slag composition and viscosity;the dumping temperature was lowered by 30-50°C by the addition of calcium ferrite pellets during the double slag process to prevent phosphorus in the slag from returning to the molten steel;and the bottom-blown gas flow was increased during the blowing process.For 40 heats of comparative experiments,the rate of dephosphorization reached 91% and ranged between 87% and 95%;the phosphorus,sulfur,manganese,and oxygen contents calculated according to the compositions of molten steel and slag as well as the temperature of molten steel at the end-point of the basic oxygen furnace process were similar to the equilibrium values for the reaction between the slag and the steel.Less free calcium oxide and metallic iron were present in the final slag,and the surface of the slag mineral phase was smooth,clear,and well developed,which showed that the slag exhibited better melting effects than that produced using the conventional slag process.A steady phosphorus capacity in the slag and stable dephosphorization effects were achieved.