Quartz Mining Waste for Concrete Production: Environment and Public Health

Brazil, one of the largest ore producers in the world, holds 95% of the world’s quartz reserves. The aim of this research is to enhance mitigation measures in quartz ore exploration common in the Serra do Espinhaço Meridional region through the specific study of a mining venture. The three (3) phases of the study were: (1) characterization of the project under study and evaluation of the impacts generated; (2) evaluation of the economic feasibility of using the waste as a coarse aggregate for concrete production; (3) evaluation of the technical feasibility of reusing this waste through analysis of compressive strength. The results of the study show potential negative impacts on occupational health from the piles of disposed waste, specifically silicosis, caused by silica dust dispersed in the air. In the economic analysis, a decrease of 49.05% was verified in coarse aggregate cost through the use of the residue. The compressive strength of the concrete was 26.80 MPa when quartz residue was used and 29.2 MPa when limestone was used. The quartz residue generated by the venture can be reused as aggregate for the production of concrete, generating improvements in environmental and health aspects.

Newer results of Monte Carlo inversion of IP data in water base protection and ore exploration

The paper presents the latest results of Monte Carlo inversion of IP data in the areas of water base protection and ore exploration. The method of determining the time constant spectrum using Monte Carlo inversion and the parameters characterizing the degree of environmental contaminations and ore deposition are presented. Among the field applications in Hungary, the investigation of the ionic pollution of the Ráckeve water base and the characterization of the Felsőtelekes waste dump of the Rudabánya iron ore mine are presented. In addition to these, the paper presents the investigation of ore deposition in the area of a gold mine in Mongolia using the Monte Carlo inversion of multi-electrode pole-dipole IP method.

Hydrogen Peroxide Ammonium Citrate Extraction: Mineral Decomposition and Preliminary Waste Rock Characterization

A commonly-used method in ore exploration is hydrogen peroxide ammonium citrate (HA) extraction, which has not typically been used in waste rock characterization. In this study, the sulfide specificity and leaching of other minerals in HA extraction was evaluated and its performance was compared with the aqua regia (AR) extraction for preliminary assessment of harmful element mobility. Samples collected from several different mine sites in Finland were utilized. The waste rock sample S contents ranged from 0.3% to 5.3%, and sums of the AR extractable elements As, Cd, Co, Cu, Ni and Zn range from 120 to 8040 mg/kg. The drainage types ranged from acid high-metal to neutral low-metal, with pH’s of 3.3–7.7. Mineralogical changes that took place in the HA solution were investigated by the field emission scanning electron microscope (FE-SEM) equipped with an energy-dispersive X-ray spectroscopy analyzer (EDS) and X-ray diffraction (XRD) methods. Results of the study showed that the HA extraction appears to be a more specific method for sulfide decomposition compared with AR extraction. Sulfide minerals, especially base metal sulfides pentlandite, chalcopyrite and sphalerite, decomposed efficiently in HA extraction. However, the Fe-sulfides pyrrhotite and pyrite only decomposed incompletely. The study showed that the HA extraction results can be used in the preliminary prediction of element mobility. Based on the results, the elevated As, Cd, Co, Cu, Ni, S and Zn leachability in the HA extraction appears to predict elevated drainage concentrations. If the HA-extractable sum of As, Cd, Co, Cu, Ni and Zn is >750 mg/kg, there is an increased risk of high-metal (>1000 µg/L) drainage. Therefore, the HA extraction data, e.g., produced during ore exploration, can be utilized to preliminary screen the risks of sulfide related element mobilities from waste rock material.

Petrology of Precambrian metagranites and heavy mineral chemistry of the Olounou area within the Cameroon mineral belt (Ntem Complex, South Cameroon): relationships with the Fe-mineralization

The petrology of Achaean biotite- and amphibole-rich metagranites, the geochemistry of Fe-occurrences and heavy mineral concentrations in stream sediments from Olounou (Ntem complex) help to constrain their inter-relationships. These metagranites display granoblastic textures outlined by microcline, biotite, amphibole and oxides. Ilmenite (60 to 80%), zircon (15 to 20%) and rutile (1 to 2%) are the mineral fractions in pan concentrates. Two types of Fe-mineralization as silicified veins crosscut the above rocks: hematite± magnetite quartzites with primary hematite enclosing magnetite relicts contain high average Fe2O3 (69.05 wt %) and TiO2 (0.73wt %); banded magnetite-rich quartzites with magnetite partially replaced by hematite are characterized byFe2O3 (52.15 wt %), TiO2 (0.27 wt %), relatively high W (286 ppm) and Ni (108 ppm). Both types have Zn, Cu, Ga contents below 10 ppm, positive Eu anomalies, HREE enrichment over LREEs and low ∑REE (9.76 to 12.07). Iron and SiO2 were derived from weathering of Archean biotite and amphibole metagranites, deposited in existing Post-Archean intra-cratonic basins under greenschist facies and impacted by sub-marine hydrothermal solutions. These results are genetically comparable to other Precambrian BIFs and underline the iron potential of Olounou. They equally contribute to iron ore exploration in Cameroon and worldwide.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5426547

Silver ore exploration in the Southern Urals

Introduction. Native historiography associates the beginning of Southern Ural industrialization with the construction of first metallurgical works in the 1740s. Historians paid attention to geological exploration in the Urals in the 17th century but they had no idea about the survey areas. Historical archeological study on the edge of the town of Zlatoust in the Southern Urals has managed to find the trace of the largest geological survey expedition aimed at silver ore exploration as far back as 1669–1673. Expedition at that time represented a major military autonomous formation (regiment) under a voivode’s (Slavic title for a war-leader) command. A large number of participants was due to the need for great manpower and protection from hostile nomads Research aim is to introduce unique discoveries in the history of mining into professional scientific use. Methodology. When analyzing the historical material, the methods of field survey and investigation on the documents of ancient mining remains have been developed. Results. The sequence of events has been retraced in the article, geological survey and mining areas and stages have been determined. Organizational structure, quantity, aims and results of the largest geological survey expedition in the history of Russia have been defined. Mining traces have been discovered being a unique monument to the history of mining in the 17th century.