Nickel laterite ores

The dissolution of goethite in acidic media and the reprecipitation of the Fe as hematite, is a crucial process in the high-temperature leaching of nickel laterite ores. At 250 °C the rate of transformation increased as the Eh of the system was lowered... 

Internal Standard Addition. An example of the use of an internal standard for phase quantification is the recent work by Madsen et in their study of the reaction mechanism of pressure acid leaching (PAL) of nickel laterite ores. This was an in situ study in which nickel laterites were reacted with sulfuric acid at elevated temperature and hydrothermal pressure to prevent the boiling of the acid. The purpose of pressure acid leaching is to dissolve any nickel-bearing phases into the acid and subsequently treat this with solvent extraction for the recovery of the nickel. There has been much ex situ work done to the reaction mechanisms of this system, but these studies have relied on the cooling of the system prior to any analytical work. 

Figure 11.5 Results of quantitative phase analysis during pressure acid leaching of saprolitic nickel laterite ore.

I. C. Madsen, N. V. Y. Scarlett and B. I. Whittington, Pressure acid leaching of nickel laterite ores an in-situ diffraction study of the mechanism and rate of reaction, J. Appl. Crystallogr., 2005, 38, 927-933. 

B. I. Whittington, J. A. Johnson, L. P. Quan, R. G. McDonald and D. M. Muir, Pressure acid leaching of arid-region nickel laterite ore part II. Effect of ore type. Hydrometallurgy, 2003, 70, 47-62. 

J.A. Johnson, etal. Process Water Salinity Effects in the Pressure Acid Leaching of Cawse Nickel Laterite Ore, Chloride Metallurgy 2002, E. Peek, G. Van Weert, Eds., CIM, Montreal, Quebec, Canada, vol. 1, 2002, 339-354. 

J.A. Johnson, B.I. Whittington, Effect of Ammonium, Sodium and Potassium Sulphates and Chlorides in Pressure Acid Leaching of Western Australian Nickel Laterite Ore, Pressure Hydrometallurgy, M.J. Collins, V.G. Papangelakis, Eds, CIM, Montreal, Canada, 2004, 199-214. 

J. Johnson, et al.. Effect of Eh in the High Pressure Acid Leaching of Nickel Laterite Ores, International Laterite Nickel Symposium 2004, W.P.Imrie, D.M. Lane, Eds, TMS, Warrendale, Pennsylvania, U.S.A., 2004, 273-288. 

Primary nickel is produced from both lateritic and sulfidic ores. Although currently the majority of nickel is produced from sulfidic ores, the production of nickel from lateritic ores is increasing and may overtake nickel production from sulfidic ores [1]. Lateritic ores are formed by prolonged weathering of ultramafic rocks. Typical mineralogical profile of nickel laterite ore bodies is as follows [2, 3] ... 

In nickel laterite ore agglomeration, the moisture contents reported lie within a wide range (10-30%) due to the nature of the ores [7 8 9 10]. Thus, in this study the moisture content was varied between 10 to 25% on a dry ore basis. Moisture content includes water and acid in its calculation as shown in Equation 1. 

Experimental Study on Reduction-Magnetic Separation Process of Low-grade Nickel Laterite Ore... 

Table 2.1 Chemical compositions of nickel laterite ore (unit mass%).

Bo li, Hua Wang, Yonggang Wei. The reduction of nickel from low-grade nickel laterite ore using... 

J. M. Floyd B. W. Lightfoot and W. E. Short, Application of the Ausmelt Process to Treatment of Nickel Laterite Ores , Nickel/Cobalt Laterites Seminar, Alta Metallurgical Services, Melbourne, Australia, 4-5 May, 1995, (Unpaged). 

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