Crude Ore Research Articles

Extraction of a low grade zinc ore using gravity and froth flotation methods

Extraction of low grade zinc ore found in Gumau- Toro town was carried out using gravity and froth flotation methods. Analysis of the chemical composition reveals that the crude ore contains 20.20% Zinc and other related minerals such as 66.72% SiO2, 2.36%.Pb, 16.62%Fe, 0.001%Ag, these are impurities that hindered the grade of zinc in this ore from appreciating. Fractional and grain sieve size results revealed that the liberation size of the ore is at -355+250μm assaying 32.41%Zn. At this liberation sieve size, the low grade zinc ore was subjected to four different beneficiation methods using five kilograms (5kg) each as charge into Wilfley shaking Table, Humphrey spiral concentrator, Air floating Machine and one kilogram (1kg) for froth flotation. Resulting products (concentrate and tailing) from these processes were analyzed using instrumentation method. Percentage recovery of each applied process was calculated. This was used to ascertain that the use of froth flotation that gives 74.32%Zn at a recovery of 84.62% stands out the best method for zinc extraction towards value addition to the low grade crude zinc ore. ©JASEMKey words: Extraction, Upgrading, Gravity, Froth flotation, Mineral, Fractional analysis.

Cohesive strength of iron ore granules

We present an experimental and numerical investigation of the mechanical strength of crude iron ore (Hematite) granules in which capillary bonds between primary particles are the source of internal cohesion. The strength is measured by subjecting the granules to vertical compression between two plates. We show that the behavior of the granules is ductile with a well-defined plastic threshold which increases with the amount of water. It is found that the compressive strength scales with capillary cohesion with a pre-factor that is nearly independent of size polydispersity for the investigated range of parameters but increases with friction coefficient between primary particles. This weak dependence may be attributed to the class of fine particles which, due to their large number, behaves as a cohesive matrix that controls the strength of the granule.

Chemical distribution of hazardous natural radionuclides during monazite mineral processing

It is very important to calculate the radioactivity concentration for low-grade monazite ore (50%) and different other materials produced as results of chemical processing stages to avoid the risk to workers. Chemical processing of low-grade monazite pass through different stages, washing by hydrochloric acid and digested with sulfuric acid and influence of pH on the precipitation of rare earth elements has been studied. The radioactivity concentrations of 238U(226Ra) and 232Th as well as 40K were calculated in crude low-grade ore and found to be 54,435 ± 3138, 442,105 ± 29,200 and 5841 ± 345 Bq/kg, respectively. These values are greatly higher than the exempt levels 25 Bq/kg. After chemical digestion of the ore, the results demonstrated that un-reacted material contains significant radioactivity reached to approximately 8, 13 and 23% for 238U, 232Th and 40K, respectively. The results show that 60% of 232Th are located in the digested white slurry with small portions of 238U and 40K. Most of 238U radioactivity is extracted in the green phosphoric acid which produced from conversion of P2O5 by H2SO4 into phosphoric acid. The average values of the Raeq for monazite ore, un-reacted black precipitate, white precipitate, brown precipitate and crystalline material samples were calculated and found to be 687,095 ± 44,921, 85,068 ± 5339, 388,381 ± 22,088, 313,046 ± 17,923 and 4531 ± 338 Bq/kg, respectively. The calculated values of Raeq are higher than the average world value (it must be less than 370 Bq/kg). Finally the external hazardous, internal hazardous and Iγr must be less than unity. This means that specific radiation protection program must be applied and implemented during monazite processing.

PRODUCTION OF AN INSULATION MATERIAL FROM CARPET AND BORON WASTES

Buildings are large consumers of energy in all countries. In regions with harsh climatic conditions, a substantial share of energy goes to heat and cool buildings. This paper reports an investigation of the insulation materials made from mixing carpet wastes with a solution with added crude colemanite ore, one of boron minerals, and a solution with added colemanite wastes from a barrage. A new building insulation material was produced which is name, Halibor. Optimum mixing ratios were determined for mass production and the physical properties of the product were established. In addition, the material produced was compared with similar products used in buildings in terms of physical properties. As a result of the investigations, it was established that the product provides high heat and sound insulation and can be used easily in building and construction industry.

Metallization of siderite ore in reducing roasting

The behavior of the initial ore and the concentrate of magnetoroasting beneficiation during metallization under the conditions that are close to those for reducing roasting of iron ores in a rotary furnace is studied in terms of works on extending the field of application of Bakal siderites. A difference in the mechanisms of the metallization of crude ore and the roasted concentrate is observed. The metallization of roasted concentrate lumps is more efficient than that of crude siderite ore. In this case, the process ends earlier and can be carried out at higher temperatures (1250–1300°C) without danger of skull formation.

Аналіз сучасних методів контролю якості рудної сировини

Аналіз сучасних методів контролю якості рудної сировини

THEORETICAL ANALYSIS OF HYDRODYNAMIC PARAMETERS OF PARTICLE MOVEMENT IN CENTRIFUGAL DENSE-MEDIA SEPARATION UNIT

A short description of centrifugal dense-media separation unit with two-layered isolation medium designed for improvement in the quality of gravity concentrates is given in dressing crude ore of color, rare, and precious metals; its basic diagram is shown. The solution of differential equations describing the separated particle movement in the working area is considered. As a result, analytical expressions of the most important hydrodynamic parameters of easy and heavy particle movement, i.e. their radial and longitudinal speeds necessary for correct calculations of the basic constructive elements of the separation unit, are obtained. The tests of a laboratory model of the device on artificial mixtures of quartz and galena have shown that the mutual contamination of separation products does not exceed 5 %.

Recovery of the Rare Metals from Various Waste Ashes with the Aid of Temperature and Ultrasound Irradiation Using Chelants

The incineration fly ash (IFA), molten fly ash (MFA), thermal power plant fly ash (TPP-FA), and nonferrous metal processing plant ash (MMA) have been screened in terms of the following rare-termed metal contents: B, Ce, Co, Dy, Eu, Ga, Gd, Hf, In, Li, Lu, Mn, Nb, Nd, Ni, Pr, Rb, Sb, Se, Sm, Sr, Ta, Tb, Te, Ti, Tm, V, W, Y, and Yb. The pseudo-potential for recycling of the waste ashes, as compared to the cumulative concentration in the crust (mg kg−1), was determined as follows: MMA > IFA > MFA > TPP-FA. The comparison with the crude ore contents indicates that the MMA is the best resource for reprocessing. The recovery of the target metals using aminopolycarboxylate chelants (APCs) has been attempted at varying experimental conditions and ultrasound-induced environment. A better APC-induced extraction yield can be achieved at 0.10 mol L−1 concentration of chelant, or if the system temperature was maintained between 60 to 80 °C. Nevertheless, the mechanochemical reaction induced by the ultrasound irradiation has been, so far, the better option for rare metal dissolution with chelants as it can be conducted at a minimum chelant concentration (0.01 mol L−1) and at room temperature (25 ± 0.5 °C).

Pre-Concentration of Ultrafine Crushed Hematite Ores

In this study, a lean hematite ore was crushed to produce ultrafine particles using a high pressure grinding roll and then pre-concentrated using a high gradient magnetic separator with a steel rod matrix to reduce the ore tonnage for milling and grinding energy consumption. Pilot test results showed that the primary concentrate grade was increased by 6.98 percentage points from the crude ore with 18.34% Fe at an optimum pre-concentration condition obtained using a matrix with a rod diameter and a rod gap that both measure 4 mm. The concentrate recovery reached a maximum of 86.13% with a tailings yield of 37.61%. Primary concentrates were separated further, and clean concentrates with a grade of 67.15% were obtained.In a magnetic field around a matrix rod, the magnetic capturing force on coarse hematite particles was increased, but such force on fine hematite particles was decreased as the matrix rod diameter increased at the same background magnetic field intensity. Considering gravity and viscous resistance of locked particles, the matrix with large diameter rods (e.g., 4 mm) could effectively and completely recover these particles. By contrast, the matrix with small diameter rods (e.g., 1 mm) could efficiently recover fine particles but not coarse particles such as lean-locked particles.

Separation Test of Fluorite Ore with Barite in Hunan

A detailed beneficiation test of fluorite ore with barite from Hunan area was studied. The grade of the fluorite in the crude ore is 56.47% and the barite is 17.32%, mainly gangue minerals is quartz. According to the properties of the ore, by comparing the results of various tests, we decided take the procession as follow: after the grade classification, coarse grain tailing by the jig, and then bulk flotation fluorite and barite ore, mixed flotation concentrate then float the fluorite and restrain the barite, the fine particle come into the shaking table to concentrate the barite fine particle concentration. Finally the grade of fluorite concentrate is 96.54% and recovery rate is 89.77%; the grade of barite concentrate is 88.78% and recovery rate is 97.46%. Then we achieved the good test indicator.

Bioleaching of low-grade copper sulfide ores by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans

The grown conditions of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were investigated, and then experiments were conducted to research the bioleaching behaviors of crude ore of copper sulfide and hand-picked concentrates of chalcopyrite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The experimental results show that the bacteria grow best when the temperature is (30±1) °C and the pH value is 2.0. The bacteria concentration is 2.24×107 mL−1 in this condition. It is found that the copper extraction yield is affected by the inoculum size and the pulp density and the extraction yield increases as the inoculum size grows. The bioleaching rates reach their highest point in sulfide copper and chalcopyrite with a pulp density of 5% and 10%, respectively. Column flotation experiments of low-grade copper sulfide ores show that the bioleaching recovery reaches nearly 45% after 75 days.

Separation Test of Oxide Copper Ore in Yunnan

A task of a refractory oxide copper ore in Yunnan has been studied, the grade of copper is 2.76% in crude ore. This ore has high oxidation and deep combination, the oxidation ratio is 42.32% and the combination ratio is 33.01%, so it is difficult oxide copper. Because the sulfide copper in crude ore containing 21.27%, so by experimental research, we decided to adopt the process of floating copper sulfides, and then sulfide oxide copper. In the flotation of oxidized copper minerals, we take the process of desliming, the copper minerals have recycled efficiently, while making a small precious metal--silver has been associated enrichment. Through closed-circuit test, we obtained the final concentrate, which the grade of copper is 20.38%, the recovery of copper is 65.44% and the grade of silver is 80.15g/t.

Separation Test of Ilmenite in Guizhou

The grade of the TiO2 in the crude ore is 5.84%, the grade of the iron is 28.38%, and the form of the TiO2 mainly is ilmenite. Because of the TiO2 dense symbiosis with the iron, so the difficulty of the study is the effective separation of TiO2 and iron. After testing we decided take the process of grinding the crude ore, then get the iron concentrate through the high gradient magnetic separation. After tailing by the spiral chute, the concentrate through the shaker for the final selection of titanium concentrates. As a result, we attained satisfying selecting targets through closed-circuit test: The grade of TiO2 is 45.38% and the recovery is 70.64% in the TiO2 concentrate. The grade of iron is 57.42% and recovery is 63.80% in iron concentrate.

북한 광물자원 부존 및 개발현황 개요

북한의 광물자원 부존량 및 생산 현황을 종합하면, 북한에서 부존규모가 큰 주요 광물종은 마그네사이트, 석회석, 석탄(무연탄), 인상흑연, 철, 금, 은, 연, 아연 등으로 판단된다. 기타 동, 몰리브덴, 중석, 인광석 등이 잠재성이 큰 광물자원으로 평가된다. 북한의 광물자원 수출 대상국은 중국으로서 주요 수출 광물로는 무연탄, 철광석이 75%로서 압도적으로 우세하다. 수출국은 중국 외 EU국가이나, 중국 수출이 70%에 달한다. 북한은 금 매장량 약 2,000톤과 연간 생산량은 약 2 톤(금속기준)이며, 대표적 광산은 수안, 홀동, 대유동광산이며, 6개 금 제련소가 운영 중이다. 철 매장량은 Fe 63.5% 기준으로 약 43억 톤, 연간 생산량은 약 5백만 톤, 주요 철광산은 무산, 리원, 북청, 은율, 신원, 재령광산이며, 7개 제철소 및 제강소가 운영 중이다. 연-아연 매장량은 금속 기준으로 연이 약 4.7백만 톤, 아연이 15백만 톤, 연간 생산량은 금속 기준 연이 약 26,000 톤, 아연이 금속 기준 50,000 톤이다. 주요 연-아연 광산은 검덕, 은파, 성천광산이며, 6개 제련소가 운영 중이다. 마그네사이트 매장량은 MgO 95% 기준으로 약 28억 톤, 최근 연간 생산량이 정광 기준 150,000 톤, 주요 광산은 룡양, 대흥, 쌍룡광산이며, 5개 마그네슘 내화물공장이 가행중이다. 인회석 매장량은 <TEX>$P_2O_5$</TEX> 30% 기준으로 약 3.4억 톤, 최근 연간 생산량은 원광석 기준 약 300,000 톤, 주요 광산은 대대리, 동암, 풍년광산이다. 석탄은 북한에서 중요한 전략 연료광물자원으로 인식되고 있으며, 주 에너지원이다. 석탄 매장량은 186억 톤, 연간 생산량은 2천만 톤이다. 주요 석탄광산은 평남에 집중되고 있으며, 직동광산이 북한에서 가장 큰 석탄광산이다. The potential mineral resources in North Korea are magnesite, limestone, coal, graphite, iron, gold, silver, lead, and zinc. North Korea is mainly exporting coal and iron to China(70%) and EU countries. Gold ore reserves(or resources) in North Korea are about 2,000 tons and annual production is 2 tons based on metal. Major gold mines are Sooan, Holdong, and Daeyoodong mines and six smelters are operating. Fe ore reserves (or resources) are 4.3 billion tons and annual production is about 5 million tons based on 63.5% Fe. Major iron mines are Moosan, Leewon, Eunryul, Shinwon, and Jaeryong and 7 smelters are operating. Pb and Zn ore reserves(or resources) are Pb 470,000 tons and Zn 15 million tons, and annual productions are about Pb 26,000 tons and Zn 50,000 tons based on metal respectively. Major Pb-Zn mines are Gumdock and Seongcheon mines. Magnesite ore reserves(or resources) are 2.8 billion tons (95% MgO) and annual production is about 150,000 tons. Major magnesite mines are Ryongyang, Daeheung Youth and Ssangryong mines, and 5 magnesium refractory factories are operating. Apatite ore reserves(or resources) are 340 million tons(30% <TEX>$P_2O_5$</TEX>) and annual production is about 300,000 tons(crude ore). Major apatite mines are Daedaeri, Dongam and Poongnyen mines. Coal is established as an important strategic fuel mineral resources and is a major energy source in North Korea. Coal ore reserves(or resources) are 18.6 billion tons and annual production is about 20 million tons. The main coal fields is located in southern Pyongan and the Jigdong mine is the biggest in North Korea.

Influence of Collectors on Flotation of Fine Tin Middlings after Gravity Separation

The study was aimed to recover tin minerals from fine tin middlings from Laos after gravity separation. The middlings had a tin grade of 0.5%, belonging to a refractory ore, so flotation was used to recover tin of them. Based on the research of influence of collector on flotation of fine tin middlings, an optimum index was obtained in the closed-circuit flotation. Finally, the concentrate with a tin grade of 3.45% and a tin recovery of 59.85% was obtained, which was concentrated by 6.9 times compared with the crude ore, which greatly improved the economic benefit for the concentrator and highly increases the efficiency of separation.

“Memory loss” during mineral processing: Application to base metals traceability

Traceability of concentrates is required to introduce transparency in the trade of raw minerals. In this context traceability may be considered as a kind of inversion process: studying the product sold (i.e. the concentrate) in order to identify the original ore, in terms of ore deposit-type and if possible, location. The difficulty of making this inversion from concentrate toward bulk ore corresponds to the “memory loss” of the crude ore which occurs during mineral processing. Based on textural characterization and the chemical composition of the material at different steps of processing, as well as the minimum residence corresponding to each step, an estimation of this “memory loss” is proposed and the relations between memory loss and global kinetic rate of flotation are established.“Memory loss” calculations are applied to the Neves Corvo plant. Throughout the process, the parameter of memory loss increases respectively from 0 to 195.06 for Cu; 0 to 46.15 for Zn and 0 to 0.43 for Fe. The “global memory loss”, namely as the “experimental memory loss”. For the Neves Corvo plant at the moment of the study this “experimental memory loss” was 14,146min for Cu, 3408min for Zn and 36min for Fe. The results show that “memory loss” is greater for Cu than for Zn, thus emphasizing the importance of secondary elements for traceability purposes.

Beneficiation Process Optimization Study on a Low-Grade Hematite Ore

A hematite has low grade, fine disseminated size andcomplex disseminated relations, which are refractory iron ore. Using SLon pulsating high gradient magnetic separator, induction intensity 8500Oe, pulsating 20mm stroke, stroke of 120 beats / min), a crude iron ore concentrates a grade of 35.93.%, the recovery rate of 82.39% is obtained through high intensity magnetic separation.( The final iron concentrate with TFe grade of 64.83%,yield of 14.55% and iron recovery of 35.74% from the raw ores with TFe grade of 26.29％ was obtained, with the first stage grinding size being 50% -0.074mm and the second stage,95% -0.074mm.

Research on the Application of Mo-Ni Ore Pre-Discarding Tailings by Small-Diameter Hydrocyclone

For the Mo-Ni ore that mineral composition is complex, and the grade is relatively low, the flotation’s effect is not good in advance for enrichment, because of the influence of fine grained level gangue minerals. The small diameter hydrocyclone were used to pre-discard tailings, with the best pulp density and feed pressure, the rate of throwing is the 30%, and then the flotation obtained a good beneficiation index. The crude ore that contains Mo 2.04 %, Ni 1.87 %, through the closed-circuit test won a concentrate that the grade of Mo is 8.94 % and the recovery is 91.86 %, the grade of Ni is 6.75 % and the recovery is 86.79 %. Compared with the single flotation process, it improved the flotation effect and the enrichment ratio of Mo Ni, and realized the efficient enrichment of Mo-Ni.

Desulfurization Process of High-Sulfur Coal by Full-Flotation

The coal sample from the Shijiazhai mine located in the east of Yunnan province of China, is characterized with high ash and sulfur content which are 64.90% and 8.66% respectively. Analysis results indicate that coal and pyrite are the valuable minerals that can be recycled from the crude ore. According to the properties of the ore, a full-flotation flowsheet is proposed to process the ore. The coal is separated by depressing the pyrite firstly, then the pyrite is activated and flotated. Based on the regulating of reagent scheme and flowsheet process, the optimum small-scale closed circuit experiment is conducted to obtain a coal concentrate with a yield of 37.18%, assaying 41.10% C and 5.38% S at a C recovery of 83.05%, and a S concentrate with a yield of 6.18%, assaying 9.04% C and 42.49% S at a S recovery of 30.56%, which could provide technical support for the building of the plant.

Heat-insulating material on the basis of silica-containing wastes formed in crude ore recovery in Kola Peninsula

The possibility was demonstrated for obtaining a heat-insulating material from silica-containing product formed in acid treatment of nepheline produced at the Open Joint Stock Company Apatit. Granular porous material based on silica fume was prepared. The heat conductivity of the bulk material was 0.075–0.08 W m−1 deg−1.