Molybdenum News Center

The benefits and advantages of the present invention are achieved by a process including the steps of forming a substantially uniform particulated reaction mixture composed of molybdenum oxide, an iron bearing material such as a high grade iron ore, a reductant and a slag fluxing agent which are present in controlled proportions. In accordance with a preferred embodiment of the present invention, the reductant comprises a mixture of silicon and metallic aluminum present in proportions on a weight ratio basis of about 4:1 to about 10:1 parts silicon for each part aluminum, and wherein the total reducant is present in an amount substantially equal or slightly in excess of that stoichiometrically required to react with the oxygen associated with the molybdenum oxide and iron bearing constituents in the reaction mixture. An initial portion of the reaction mixture is charged into a refractory-lined crucible and is ignited by a suitable fuse to initiate the exothermic thermite reaction with a second portion of the mixture being progressively added and reacted so as to form a molten mass of ferromolybdenum having a layer of molten slag floating across the upper surface thereof. The reaction mixture is fired and after a suitable settling period, such as 40 - 45 minutes, droplets or prills formed in the slag mass have settled and entered the molten ferromolybdenum mass. At the conclusion of the settling period, the predominant portion of slag is preferably withdrawn from the upper stratum of the slag layer. After a cooling period, such as a period of 1 - 6 hours, to effect a solidification of the ferro-alloy mass, an additional reaction mixture is added and a second reaction commenced. The intermittent withdrawal of the predominant portions of molten slag in accordance with the preferred embodiment of this invention increases the effective volume of the crucible and the successive reactions are repeated until substantially the entire crucible has been filled.

 

The resultant reaction mass is thereafter cooled to effect a solidification thereof, and the multi-layered ingot comprising layers of ferromolybdenum alloy of controlled thickness separated by intervening residual slag layers is cleaved to enable removal of the slag sections, and the individual ferro-alloy buttons are crushed and screened to sizes consistent with the intended end use of the ferro-alloy. The molten slag portions withdrawn from the crucible are substantially devoid of any entrapped molybdenum values and can be discharged to waste, while the relatively thin layers of residual slag between layers of the ferro-alloy can be advantageously processed for recovery of the entrapped molybdenum values therein. The presence of residual slag layers in the ingot also facilitates cleavage of the multi-layered ingot into individual ferro-alloy buttons which may be further enhanced by the addition of refractory materials to the residual slag layers between succeeding reactions.

More molybdenum product: http://www.molybdenum.com.cn
Tel: 0592-5129696 Fax：0592-5129797
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Price: http://www.chinatungsten.com