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Abstract
This paper presents a case study at an Indian iron ore mine where controlled blast patterns were meticulously planned after conducting a few trial blasts for conducting blasts near numerous sensitive structures. A new screening plant for the mine had to be constructed on a hilly terrain in the vicinity of many sensitive structures such as residential huts, gas stations, gas storage facilities, structures of the existing screening plant, mine water reservoirs, etc. The test blasts were conducted at selected locations of the hilly terrain with varying geometric parameters in order to understand the results of the interaction between rock and explosives in the area. The effects of blasting, i.e., ground vibration, air overpressure, rock flight, etc., were evaluated and measured. Based on the results the results of test blasting and vibration data analyses from various iron ore mines in India with similar topographic conditions, three blasting zones were distinguished: critical, semi-critical and non-critical have been defined considering the nearness and sensitiveness of different structures. For each zone, the blasting parameters were developed, i.e., load, spacing, number of holes, blast charge per delay, type of explosive, etc. Using the developed controlled blasting patterns, development work near sensitive structures progresses safely. The developed controlled blasting patterns and methods can be used as aids for similar work in the absence of adequate scientific evaluation results.
Key words: controlled blasting, screening plant, iron mine, hard rock, excavation, blast vibration, explosive, drilling and fblasting, damage.
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Abstract
In the present investigation, an attempt is made to synergize the effects of textural, physical and chemical characteristics of placer deposits. These deposits are associated with lean and off-grade placer heavy minerals, which typically exhibit variations in total heavy minerals, texture and composition. They are found all along the coastal stretch of the Bay of Bengal, from Chatrapur to Puri Dists, Odisha, India. The aim is the recovery of total heavy minerals using various models of gravity concentrates. The results of the present study reveal that the Mozley table produced a concentrate containing 93.2% THM. In comparison, the gravity table, HG8 spiral, CT spiral and Humphrey spirals yielded concentrates with 92.2%, 92.9%, 93.6%, and 98.2% THM, respectively, from a feed sample containing 4.72% THM. Additionally, it was observed that the performance of the spiral depends on both the feed grade and the texture analysis of the input material.
Key words: Beach Sand, Placer, Heavy Minerals, Mineral Separator, Spiral Concentrators.
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Abstract
The different genesis of copper-nickel objects requires the use of different technologies for their enrichment. A scheme has been proposed for processing copper-nickel ore tailings, first by granulating the tailings with sulfuric acid, storing them at below-zero temperatures, and then followed by heap leaching of granules was proposed. The effect of different ratios of tailings to binder during granulation on the subsequent recovery of the metals was considered. At a ratio of S:L = 6:1, 44.4% nickel and 8.9% copper were recovered during the 40-day experiment. For ore processing, the efficiency of heap leaching with a 2% H2SO4 solution using technogenic ores from the Nud Terrasa was considered and Allarechensk deposits ores was studied, as no additional ore preparation was required. Atthe end of the experiment, 12.8% nickel and 10.2% copper were recovered from the Nud Terrasa ore, and 10.2% nickel and 4.4% copper were recovered from the ore of the Allarechensk technogenic deposit. The ore from the Nud II deposit and a rich sample of the Allarechensk ore were processed by low-temperature roasting with ammonium sulfate. From the ore of the Allarechensk technogenic deposit, 91.5% of nickel and 94.8% of copper were recovered. The results obtained may be of significant practical interest, especially in the Arctic zone.
Key words: : low-temperature roasting; heap leaching; sulfuric acid granulation; copper; nickel; Arctic zone.
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Abstract
Three-dimensional (3D) surface imaging systems have gained popularity in monitoring the status and condition of separation processes by characterizing the internal and external structures of particles such as size, shape, density and composition. This review article mainly focuses on demonstrating the state of the art of 3D imaging systems in mineral processing based of the recent growth in 3D sensors. The structure of this manuscript comprises an overview of the two 3D imaging systems, including RhoVol and X-ray computed tomography, based on the basic principles. Their applications in mineral processing are then explained. By integrating with other imaging tools and the 3D printing technology, 3D surface imaging systems will play an important role in the automation and control of mineral processing in the future.
Key words: : 3D sensors, mineral processing, RhoVol, computed X-ray tomography, automation.
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Abstract The feasibility of targeted modification of the spectral properties of weakly and anomalously luminescent diamonds by modifying reagents containing luminophores based on sulfides and zinc orthosilicate, characterized by medium and low deviation of the luminescence signal from that of natural diamond. It was found that the hydrophobic treatment of inorganic luminophores with potassium butyl xanthate could increase the recovery of anomalous luminescent diamonds in the process of X-ray luminescence separation up to 80%. Organic collectors (optically transparent oil products with high extractability for luminophores and adhesion to diamonds) based on technical-grade diesel fuel and catalytically cracked heavy gas oil are recommended for the luminophore-containing compositions. The feasibility of reducing the fixation of luminophores on the surface of kimberlite grains using sodium hexametaphosphate, sulfonol, carboxymethylcellulose and liquid glass was demonstrated. The application of these reagents in low-salinity water provides decreasing coating of kimberlite grains with luminophores while maintaining the required concentration of luminophores on the surface of diamonds. Semi-industrial tests with an LS-D-4-03N separator proved the possibility of complete recovery of weakly and anomalously luminescent diamonds after treatment of XRS tailings with the modifying reagents.
Key words: : diamonds, separation, X-ray luminescence, signal modification, luminophores, collectors.
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