Laterites chemical composition

Table 1 Nickel laterite chemical composition (mass fraction %)... 

McFarlane, M.J. (1983b) A low level laterite profile from Uganda and its relevance to the question of parent material influence on the chemical composition of laterites. In Wilson, R.C.L. (Ed.) Residual Deposits Surface Related Weathering Processes and Materials. Special Publication 11, Geological Society of London, pp. 69-76. 

The first point of discussion is the influence of the bedrock nature on the chemical composition of waters. We can see in Table II and in Fig. 6 that waters in the chloritic schist or argillaceous sand areas do not differ from those in the granitic area. This is not surprizing, in spite of the well-known control of rock mineral on the groundwater composition (M. Schoeller, 1962 Tardy, 1969) in fact, in the whole bioclimatic sequence considered, the lateritization processes have destructed all the primary minerals, except quartz, and the weathering minerals are always the same kaolinite, iron oxide and oxy-hydroxide, the stabilities of which in the surface are very great. 

The chemical composition of 5 selected laterites (Sivarajasingham et al., 1962) is given here in Table 20.1. These data emphasize the extremely high content of the sesquioxides... 

CHEMICAL COMPOSITION (%) OF SELECTED LATERITES (from SIVARAJASINGHAM et al 1962 reproduced by permission of Academic Press)... 

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

In order to find out the phase composition of fine laterite ore reduced with reduction temperature of 1375°C, the atomic ratio of C/O of 1.2, and the percentage of CaO of 12%, the samples were examined by X-Ray fluorescence(XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS). The chemical compositions of the fine ore by reduction-magnetic separation was shown in Table 3.1, the XRD pattern of fine ore by reduction-magnetic separation was seen in Fig.3.5, and the SEM pattern of fine ore by reduction-magnetic separation was shown in Fig.3.6 and the chemical compositions of observed district in SEM pattern was shown in Table 3.2. 

Fig.3.6 SEM pattern of the fine ore by magnetic separation of laterite reduced. Table 3.2 Chemical compositions of observed district.

Additive materials for clinker production may be needed for correcting the chemical composition of the raw mix, e.g., materials providing Fe, Si02 or AI2O3, more particularly the most inexpensive ones that can serve the purpose, e.g., roasted pyrites or low-grade iron ore, laterite, quartz sand or quartziferous weathering products of metamorphic rocks, and bauxite. 

Nickel laterite is nickel mineral changed by weathering, etching, enrichment, and then it turns loose clay-like, composed of iron, aluminum, silicon, and some hydrous oxides. The element and moisture content are rich in this kind of ore. The elemental composition and content (Table 1) can be obtained by XRF elemental analysis and chemical analysis.XRD demonstrated that host minerals of the iron-enriched and magnesium-depleted version of laterites are mainly ferric iron oxides, typically goethite, FeO(OH), and nickel embedded in the mineral is mainly as the pattern of NiO (Figure 1). All of the samples came from Baosteel. 

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