Celestine and the Process of Celestine Ores

Celestine ores are the main form strontium production for other material science and engineering applications. Depending on the synthesis goals, the methods of celestine ores vary in different laboratories. Main methods of extraction include a ”black ash” process, a co-precipitation process, or a combination of both methods to produce a strontium compound that is accessible for utilization in the industry. The first step in celestine ores is identifying the mineral through physical properties tests and other methods such as an x-ray diffraction method or RAMAN spectroscopy method which analyzes intensity peaks. The intensity peaks measured in the techniques can be compared and correlated to existing data sets of the mineral, resulting in a conclusive test of mineral identification.

Physical Properties

Experimental Data
Hardness 3.0-4.0
Fracture Conchoidal
Streak White/None
HCl Effervesces
Luster Glassy
Color White, milky, slight blue tint
Magnetism None

Data base source
Hardness 3.5-4.0
Fracture Brittle - Conchoidal
Streak White
Luster Vtireous (Glassy)
Color White, gray, reddish white, brownish white
Magnetism N/A

Table 1 is a data set measured experimentally involving observational physical properties testing such as hardness, streak, effervescing, luster, color, and magnetism. These qualitative values are compared to a data base source, table 2, of celestine to correlate relationship between properties. This method is important as an initial evaluation of the mineral sample before moving onto laboratory characterizations and measurements of the sample.

Characterization of Celestine
XRD Analysis
The diffraction of x-rays by matter results from the combination of the scattering by each individual atom and the interference between the waves scattered by these atoms (Katz 1964). In a mathematical approach, Bragg’s law gives the angles for coherent and incoherent scattering from a crystal lattice. It is defined as:

\begin{equation} 2dsin\theta=n\lambda\nonumber \\ \end{equation}

where n is a positive integer, lambda is the wavelength, d is the inter-planar distance, and theta is the angle of constructive interference. The computations of diffraction patterns obtained by measuring the intensity of scattered waves as a function of scattering angles result in a unique crystal lattice definition. In the experimental data, the angles of measurement started at 5o and ended at 75o with approximately 0.01o partitions. The range in angles allow for scattered waves at different angles to analyze the crystal lattice definition measured and produce a diffraction pattern.

X-ray diffraction analysis (XRD) of the unknown mineral sample shows that the mineral is mainly from celestine SrSO4 in relation to XRD analysis data taken from the RRUF data base. The diffraction peaks correspond to the d-spacings which allow for the identification of minerals because of each unique set of d-spacings.

X-Ray Diffraction graph of celestine
The five highest peaks [021] occurs at 27.07 2 theta. [210] occurs at 28.10 2 theta. [121] occurs at 30.09 2 theta. [211] occurs at 32.79 2 theta. [212] occurs at 44.27 2 theta. The blue line represents experimental laboratory data. The red line represents the analysis of celestine through the RRUF data base.