Thermodynamic And Experimental Study On Valuable Elements Recovery From High Speed Steel Solid Waste

This subject focuses on the recycling of valuable elements in high-speed steel solid waste,the EAF smelting method was used in the experiment.Sampling analysis was carried out from steel water,slag sample during the smelting and recovery process,the content of slag was analyzed by XRF,the composition of steel sample was measured by Spectroscope,explore the change of the recovery rate of valence elements after adjusting slag;the phase analysis was performed by XRD and then composition of slag is determined.The calculation model of slag interaction concentration was established based on the coexistence theory to explore the factors affecting the reduction and desulfurization of vanadium in the recovery process under the theoretical calculation,and comparing the results.In general,the main conclusions obtained in this paper are as follows:(1)It is feasible to recover valuable elements from high speed steel abrasive dust by EAF.The recoveries of W,Mo,Cr and V are all increased to more than 90%after slag adjustment,the ingot contains high content of composite metal elements,relatively stable composition and low sulfur content.It provides high quality raw materials for subsequent smelting.(2)Under the standard state,the transition temperature of C-V is 1415?,and the interaction coefficients of C and V activities in molten iron are fv=9.45 and fc=0.346.The activity of V₂O₃in the slag decreases with the increase of Fe O content,and decreases with the increase of Ca O,alkalinity and Al₂O₃content first and then,The values are in the order of magnitude of 10^-2?10^-1.The vanadium content in the steel sample is basically in the range of 0.7%?1.3%,and the vanadium distribution ratio between slag and steel is in the range of 3.0?4.0,which is the same as the change trend of V₂O₃activity in slag.When Ca O content is 25%,alkalinity is 2.0 and Al₂O₃content is about 30%,the maximum value is reached respectively,at the same time,appropriate Fe O content was selected.(3)In the experimental range,Ls also increased with the increase of R,but when R>5,the increase slowed down.When the slag index is between 0.25 and 0.40,the sulfur distribution is ideal.When Ca F₂<6%in the slag,Ls increases with the increase of its content.When Ca F₂?6%,Ls is at the high point;when Ca F₂>6%,Ls goes down slowly.The higher the temperature,the higher the Ks will gradually increase,and the sulfur distribution ratio will also increase,so high temperature is conducive to desulfurization.