Extraction of Manganese and Iron from a Refractory Coarse Manganese Concentrate

In this research, the coarse manganese concentrate was collected from a manganese ore concentrator in Tongren of China, and the contents of manganese and iron in coarse manganese concentrate were 28.63% and 18.65%, respectively. The majority of the minerals in coarse manganese concentrate occur in rhodochrosite, limonite, quartz, olivine, etc. Calcium chloride, calcium hypochlorite, coke, and coarse manganese concentrate were placed in a roasting furnace to conduct segregation roasting, which resulted in a partial chlorination reaction of iron to produce FeCl3, ferric chloride reduced to metallic iron and adsorbed onto the coke, and rhodochrosite broken down into manganese oxide. Iron was extracted from the roasted ore using low-intensity magnetic separation, and manganese was further extracted from the low-intensity magnetic separation tailings by high-intensity magnetic separation. The test results showed that iron concentrate with an iron grade of 78.63% and iron recovery of 83.60%, and manganese concentrate with a manganese grade of 54.04% and manganese recovery of 94.82% were obtained under the following optimal conditions: roasting temperature of 1273 K, roasting time of 60 min, calcium chloride dosage of 10%, calcium hypochlorite dosage of 5%, coke dosage of 10%, coke size of −1 mm, grinding fineness of −0.06 mm occupying 90%, low-intensity magnetic field intensity of 0.14 T, and high-intensity magnetic field intensity of 0.65 T. Most minerals in the iron concentrate were Fe, Fe3O4, and a small amount of SiO2 and CaSiO3; the main minerals in the manganese were MnO, and a small amount of Fe3O4, SiO2, and CaSiO3. The thermodynamic calculation results are in good agreement with the test results.

Optimisation of Operational Parameters of a Spiral Classifier Using Design of Experiment (DOE)

Classifying Mn Ore to improve upon the grade and the properties has become a crucial activity for the Mn industry since it increases the market value of the ore. Ghana Manganese Company (GMC) has renovated their oxide washing plant by integrating it with a spiral classifier to make a batch system operating process. Particle size of <3.35mm (Mn grade of 43-47%) obtained from the primary section of the plant served as feed to the classifier and with the plant condition (i.e. at 60 min washing time, 30 rev/min speed of spirals and feed tonnage of 6 t), Mn grade of 49% was achieved. This paper focused on the optimisation of some selected operational parameters of the classifier to obtain a Mn grade >50% using Design of Experiment (DOE). Series of test works were designed using the DOE for the classifier using the constraints of washing time (30-90 min), speed of spirals (20-40 rev/min) and feed tonnage (6-9 t). The outcome of the test work after simulation showed that all the selected parameters had a great influence on Mn grade. The spiral speed and feed tonnage correlated negatively to the Mn grade with washing time correlating positively. Operating the spiral classifier at a feed rate, spiral speed and washing time of 6 t, 25 rev/min, and 30 min, respectively, yielded Mn grade of 53%. A Confirmatory test using the established conditions gave a Mn grade of 53%, which is a 4% increment in the previous Mn grade which was 47%. The outcome of the studies is the new established operational conditions which is adhered to by the plant, producing a manganese concentrate grade ranging between 52-54%. Keywords: Design of Experiment (DOE), Spiral Classifier, Grade, Manganese

Relating to the rational utilization of manganese-containing raw materials

Data on main manganese ores deposits by Russian Federation subjects presented. It was shown, that main part of manganese ore raw materials prognostic resources are concentrated in Altaj-Sayan and Enisej-East-Sayan metallogenic provinces. Estimation of metallurgical value of manganese ores deposits, located at the territory of Altaj-Sayan metallogenic province, carried out. A technological flow-chart of manganese-containing raw materials elaborated, comprising high quality manganese concentrate obtaining, its preparation, synthesis of marokite and mono-phase CaMnO3 material, marokite briquetting with a reducing agent and application for steel processing in ladle-furnace facility. A possibility shown to utilization of CaMnO3 mono-phase material mixed with a reducing agent and high quality manganese concentrate for production of metal manganese. Thermodynamic calculations and experiment studies on polymetallic manganese-containing raw material beneficiation enabled to determine main technological parameters of extraction and elaborate a technological flow-chart of beneficiation. The elaborated technology enables to obtain high quality manganese, nickel, iron and cobalt concentrates. Application of optimal technological parameters of beneficiation enables to extract from a polymetallic manganese-containing raw materials up to 95–97% of manganese, 98–99% of nickel, 96–98% of iron. It was shown, that it is reasonable to use the manganese concentrate for low phosphor metal manganese smelting, that will enable to decrease the dependence from manganese-containing materials import. A technology of steel alloying by obtained nickel concentrate elaborated. The substitution of metal nickel by nickel concentrate will considerably reduce expenses for alloying. A technology of metalized iron production by a solid-phase reducing method from an iron concentrate also elaborated, which will enable to decrease impurities content in steel during its application.