Automated System for X-Ray Phase Analysis of the Mineral-Phase Composition of Ores and Technological Products

Abstract

The properties of complex ores that determine the technologies for their processing are inherent in the minerals and their compositions, rather than individual chemical elements. Therefore, conventional production control based solely on the chemical composition cannot fully determine the quality and technological properties of ores and enrichment products. In recent years, the use of automated X-ray diffraction quantitative phase analysis (XRD QPA) using the full-profile Rietveld method [1] has been intensively developed in global practice for controlling the mineral composition. The essence of the method is to model the diffraction pattern of the sample measured on a diffractometer with calculated diffraction patterns of its phases, which are computed from the atomic-crystalline structures of minerals. This refines the lattice parameters, peak profile of the diffraction peaks of phases, textures, and possibly the crystal structure parameters of the main phases of the sample. This makes Rietveld QPA the most accurate of the existing methods. However, the Rietveld QPA method is effective only when the qualitative mineral composition of ores and products is known and stable, and even partial changes in samples lead to errors. This impedes the development of automation of Rietveld XRD QPA in cases of significantly variable mineral composition.

Variability of Ore Mineralogy at the Olimpiada Deposit

“…XRD patterns are processed using EVA, TOPAS software package and the Information Retrieval System of X-ray Diffraction Analysis. A powder diffraction file (PDF-2) database containing 15,819 reference minerals is employed for mineral identification along with the QXRD without any reference minerals, which is based on the reference intensity ratio (RIR) method [1,2]. XRD control over the mineralogy of gold-bearing sulphide ores is supported by the synchronization of the QXRD and chemical analysis data.…”

“…Количественное определение содержаний минералов посредством метода XRD выполняется на базе дифрактометра D2 PHASER (Bruker) при излучении CoKa, монохроматор, шаг 0,01 по 2 θ, с использованием базовых программ обработки рентгенограмм EVA, TOPAS и ИПС, рентгенофазовых стандартов минералов PDF2 (15819 стандартов) для идентификации фаз, и бесстандартного КРФА по мультирефлексному методу «корундовых чисел» [1,2].…”