Abstract:
Lateritic ore is mixed with a chloridizing agent and a carbonaceous reductant to form an ore mixture for segregation roasting. The ore mixture is roasted at a temperature in the range of 1600*-2000*F. for a time duration of 0.5 to 2 hours in the presence of a reducing atmosphere provided by a mixture of CO-CO2 or H2-H2O gases to form a calcine containing nickel alloyed with iron. The calcine is subjected to a suitable treatment to recover the nickel therefrom.
Abstract:
A PROCESS IS DISCLOSED FOR THE RECOVERY OF NICKEL CONCENTRATES FROM LATERITE ORES BY SEGREGATION ROASTING WHEREIN THE ORE AFTER DRYING FOR REMOVAL OF AT LEAST PART OF THE FREE WATER IS MIXED WITH A CHLORIDIZING AGENT AND A CARBONACEOUS REDUCTAND, SUCH AS COAL OR COKE, BEFORE ROASTING. THIS MIXTURE IS HEATED TO TEMPERATURES OF 900* TO 1050*C. WHILE MAINTAINING A SLIGHTLY REDUCING ATMOSPHERE. PREFERRED CHLORIDIZING AGENT IS A MIXTURE OF SODIUM CHLORIDE AND CALCIUM OXIDE. THE RESULTING SINTER IS SUBJECTED TO SUITABLE CONCENTRATION FOR FINAL NICKEL RECOVERY.
Abstract:
Brucite in finely divided condition is collected as a high grade concentrate of brucitic ores and other magnesium hydroxides by selective temperature control of heavy liquid media during continuous treatment. Ore is initially assayed to determine the specific gravity of its brucite content and methylene bromide as heavy liquid media will be used at its usual specific gravity of 2.48 at ambient temperature. If higher grade product is desired, changes in temperature of media are developed to obtain density drop to 2.40, for example. To change back to normal production media temperature is adjusted and no change in media composition is required.