Turning waste into treasure ferroalloy slag can still be reused in this way
Since ferroalloy slag contains metals of high value, such as chromium, manganese, Molybdenum, Ni, titanium and so on, priority should be given to recovering valuable metals from ferroalloy slag, which can not be recovered at present, which can be used as construction material and agricultural fertilizer.
(1) in order to recover metal elements from slag, a lot of research work has been done at home and abroad, and metal can be recovered from a variety of ferroalloy slag. The Molybdenum -Fe slag contains 0.3% and 0.8% Molybdenum. The Molybdenum concentrate containing 4% ≤ 6% can be obtained by magnetic separation abroad and recycled. Foreign countries also use wind separation method to separate the metal in slag automatically. Wind separation can separate the original slag into slag block (> 5mm), fine slag (< 5mm) and slag powder (< 1mm), and the metal in the slag is accumulated in the slag block. The refined chromium iron slag contains about 5% metal, which can be recovered by separation. Washing silicon-chromium alloy with refined chromium iron slag in a factory in China can reduce the chromium content in the slag from 4.7% to 0.48%, increase the chromium content in silicon-chromium alloy by 1% ≤ 3%, and decrease phosphorus by 30% to 50%. The obvious economic effect has been obtained. The manganese content of electric furnace metal manganese and medium and low carbon manganese iron slag is high, and most of them are used to smelt silicon-manganese alloy in our country through various ways. For example, some plants use powdered medium manganese slag as raw material for manganese ore sintering, while others add stabilizer to medium manganese slag to prevent slag from being powdered so that it can be returned to the furnace for use. Ferrosilicon slag contains valence elements silicon carbide and manganese. It is the main element in smelting silicon-manganese alloy and can be used as burden for smelting silicon-manganese alloy. Smelting Si-mn alloy with ferrosilicon slag not only reduces raw materials, silica, coke, but also saves electricity. Tungsten iron slag contains 15% less than 20% manganese, which can also be returned to silicon-manganese electric furnace. (2) used as cement admixture and slag brick blast furnace manganese slag (including electric furnace manganese iron slag), carbon manganese iron slag and silicon manganese alloy slag can be quenched into granular slag. The formula of water quenching can be washed directly in front of the furnace, or the slag can be dragged to the slag pool by the slag tank car, and the slag can be made into water slag by means of the crane tilting the slag tank in the casting room, and the slag can be quenched by the nozzle under the flow tank. In China, ferroalloy water quenching slag is basically sent to cement plant as admixture, just like blast furnace water quenching slag. A ferroalloy factory in China sends water-quenched silicon-manganese slag to cement plant for use as admixture. When clinker is 600, the amount of water slag is 30% ≤ 50%, and 500 slag cement can still be obtained. Ferroalloy water quenching slag can also be used as slag brick. The slag brick produced by a factory in China adopts the following ingredients: ferroalloy water quenching slag 100%, gypsum 2%, lime 7%. The mixture can be put into use after wheel grinding, mixing, molding and maintenance.
