Search

The main features of the structure and gold content of the dumps of the Krestovozdvizhenskaya placer in the Middle Urals are considered. Infofrmation on drilling operations performed, gold concentration, morphological features, granulometric, and chemical composition of metal particles are presented. The studies revealed the presence of the dumps body areas with gold content identical to conditions for modern placers. The dimension of the most gold particles makes it possible to apply the hydraulic method for their industrial extraction. Characteristic evidence of a gold long stay in dumps (the formation of a high-grade coat, deposits and films on the surface, intergrowths and "gold" conglomerates, gold intermetallic compounds) are noted. Possible ways of organizing the processing of dumps are proposed.

The chemical composition of chromespinelides in the Permian sandy-gravel deposits of the western slope of the Urals was investigated by microprobe analysis. The correlation of minals is used for identification of source rocks for these sediments. They were originated by the river of the Permian age, which had the north-western flow direction and were eroded of chromite-bearing massive in the South Urals. Some details of chromites chemical composition pointed to the influence of another source rocks (for instance, Saranovskiy Massive in the Middle Urals).

Представлены результаты исследования текстурно-структурных особенностей и лабораторных экспериментов по обогащению вкрапленных хромовых руд. Несмотря на низкое содержание оксида хрома в среднем по месторождениям (5-10%), довольно высокая контрастность оруденения позволяет применить на начальной стадии обогащения рентгенорадиометрическую сепарацию с получением кускового (-100 +50 мм) промежуточного продукта со средневзвешенным содержанием 18% Cr2O3. После его измельчения и глубокого гравитационного обогащения на винтовых сепараторах возможно получение концентрата с содержанием оксида хрома выше 40%.

Scientific conference devoted to P.N. Chirvinskiy was held in the Perm State University (January 2017). The problems of mineralogy, petrology, lithology, metallogeny and geochemistry were discussed.