a b s t r a c tClay minerals are widespread in various types of mineral deposits. When present, they contribute to the high content of certain parameters such as silica, aluminium, and magnesium. This study aimed to find selectivity windows to separate hematite from a clay mineral (kaolinite) to allow reduction of the levels of silica and alumina in iron ore. The collectors used were: etheramine Flotigam EDA (EDA) and the ammonium quaternary salts: dodecyltrimethylammonium bromide (DTAB) and Tomamine Q-14-2 PG (AQ142). The depressant used was corn starch. The separation selectivity was achieved using DTAB in the pH range between 4 and 10. Using the collectors EDA and AQ142, the selectivity was obtained only in the presence of starch, at pH 10. Laboratory scale tests showed that as far as the particles size is concerned, better selectivity was achieved with finer particles. Circuit configurations including cleaner and scavenger stages, and pilot scale tests, will be required prior to a possible industrial implementation of the separation.
ResumoA aplicação de espirais concentradoras no processamento de minérios de ferro data da década de 1960 na concentração de hematita especular no Canadá. Desde então, sua aceitação tem sido ampla entre as empresas produtoras de minério de ferro. As espirais, apesar de ter um funcionamento muito simples, possui um dos mais complexos mecanismos de separação entre os métodos gravíticos. Os principais mecanismos de separação descritos na literatura são apresentados neste artigo, assim como as principais variáveis de projeto, as quais também são importantes no que diz respeito a uma melhor eficiência para o processamento de diferentes tipos de minérios, ou diferentes etapas de processo. Por fim, os principais problemas operacionais em circuitos de espirais são apresentados, com algumas sugestões de melhorias. Palavras-chave: Espiral concentradora; Minério de ferro. REVISITING SPIRAL CONCENTRATION AS APPLIED TO IRON ORE BENEFICIATION AbstractThe application of spiral concentrators in the processing of iron ores started in the 1960's for the concentration of a specular hematite ore in Canada. Since then, its acceptance has been ample among most iron ore producing companies. Spirals, although presenting very simple operating principles, have one of the most complexes separation mechanisms among all the gravity beneficiation methods. The main separation mechanisms described in literature are presented in this paper, as well as the design variables, that are of fundamental importance with respect to the achievement of a better efficiency for the processing of different types of ores or different stages in the process. The main operational problems occurring in spiral circuits are presented and some suggestions for improvements are made.
The dispersion degree of the mineral particles in the pulp is especially relevant regarding the performance of the cationic reverse flotation of iron ores. The gangue minerals should remain dispersed while hematite particles should be selectively flocculated. The present study addressed determinations of dispersion degree and zeta potential of hematite in the presence of different dispersants, classified as organic polymeric (natural and synthetic), organic monomeric, and inorganic. Special attention was paid to results achieved at pH 10, used in plant practice. For natural organic polymers, correlation was observed between the dispersion degree and the increase in the negative value of zeta potential. Some synthetic organic polymers enhance the dispersion of hematite particles despite not affecting significantly the zeta potential. Sodium silicates, irrespectively of the SiO 2 /Na 2 O ratio, at pH 10, did not impact significantly either the dispersion degree or the zeta potential.
ResumoO número de estudos a respeito de fl otação de caulinita tem crescido nos últimos anos, principalmente, devido às contribuições dos pesquisadores chineses. As bauxitas chinesas apresentam alta quantidade de aluminossilicatos, entre eles caulinita, o que prejudica sua utilização no processo Bayer. Esse trabalho apresenta resultados de testes de microfl otação de caulinita com três aminas: dodecilamina (amina primária), Flotigam EDA (eteramina) e Duomeen T (amina graxa). Dodecilamina e Flotigam EDA apresentaram efi ciente ação coletora na concentração de 1x10 -4 mol/L. DuomeenT se mostrou efi ciente em concentração mais alta, 1x10 -3 mol/L. O ponto isoelétrico da caulinita, determinado a partir de medidas de potencial zeta, ocorreu em pH = 4,6. O estudo do potencial zeta da caulinita, na presença e na ausência de dodecilamina e Flotigam EDA, mostrou que a presença de amina no sistema altera seu ponto isoelétrico. Tal variação sugere que ocorreu adsorção dos coletores na superfície da caulinita.Palavras-chave: Caulinita, amina, microfl otação, potencial zeta. Abstract
Hydrophobic aggregation of galena fine particles Agregação hidrofóbica de partículas finas de galena
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.