Extraction of Metals from Wastes of Metallurgical Production

2018 ◽  
Vol 284 ◽  
pp. 845-849 ◽  
Author(s):  
Yu.E. Tokach ◽  
Yu.K. Rubanov ◽  
O.V. Doroganova
Keyword(s):  
Iron Oxide ◽  
Thermal Reduction ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Metallurgical Production ◽  
Reduction Of Iron ◽  
Extraction Of Metals

Studies on the thermal reduction of iron oxide by using reducing agents have been carried out. Carbon-containing components and aluminum were used as reducing agent. The reduction conditions were determined.

Investigation of the process of metallized materials production from iron concentrate of hydrometallurgical enrichment of ferromanganese ores of Kuzbass

2021 ◽  
Vol 77 (6) ◽  
pp. 665-674
Author(s):  
O. I. Nokhrina ◽  
I. D. Rozhikhina ◽  
M. A. Golodova ◽  
I. E. Khodosov
Keyword(s):  
Experimental Study ◽  
Gas Phase ◽  
Solid Phase ◽  
Thermodynamic Simulation ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Isothermal Exposure ◽  
Iron Concentrate ◽  
Phase Reduction ◽  
Reduction Of Iron

Study of the processes of solid-phase reduction of iron from oxides using coals as reducing agents and the development of energy-efficient technologies for the production and use of metallized materials from concentrates obtained as a result of hydrometallurgical enrichment is an actual scientific direction in ferrous metallurgy. Theoretical studies of the processes of solidphase reduction of iron from iron-containing concentrate obtained as a result of hydrometallurgical enrichment of ferromanganese and polymetallic manganese-containing ores, by coals grades D (long-flame) and 2B (brown) were carried out by the method of thermodynamic simulation using the “Terra” software complex. The experimental study of the process of solid-phase reduction of iron from experimental mixtures was carried out in a muffle furnace SNOL 4/900 and in a resistance furnace with a graphite tubular heater (Tamman furnace). The influence of the composition and volume of gas phase, formed as a result of volatile components emission in the process of coals of two grades heating at 373–1873 K obtained, optimal temperature and consumption of coals defined, which ensure complete reducing of iron from iron-containing concentrate, compositions as well as volumes of gas phase. The influence of temperature of the isothermal exposure on the rate and degree of solid-phase reduction of iron from iron ore oxides was experimentally determined when using coals of different process grades and coke fines as reducing agents. Empirical equations of reduction degree versus time of isothermal exposure for different metallization temperatures were obtained. It is shown that the change in the degree of recovery on temperature with high accuracy was described by a linear dependence, and the change in the recovery rate on the temperature – by a power dependence. Conditions of effective metallization were determined when using iron concentrate and coals of different process grades for production of spongy metallized materials with content of Femet more than 80%, and 1.5–2.5 % C, 0.1 % S, 0.02 % P. As a result of thermodynamic simulation and experimental study of the process of iron reduction from iron concentrate, optimal consumption of coal of grades D and 2Б at temperature 1473K was determined. It was established that the best reducing agent with a minimum specific consumption is long-flame coal grade D. It was found that with an excess of reducing agent, it is possible to achieve almost complete extraction of iron from the concentrate, at the level of 98–99%.

scholarly journals The Influence of Water Reducing Agents on Early Hydration Property of Ferrite Aluminate Cement Paste

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 731
Author(s):  
Chunlong Huang ◽  
Zirui Cheng ◽  
Jihui Zhao ◽  
Yiren Wang ◽  
Jie Pang
Keyword(s):  
Setting Time ◽  
Critical Role ◽  
Hydration Product ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Hydration Process ◽  
Early Hydration ◽  
Cement Pastes ◽  
Hydration Rate ◽  
Aluminate Cement

The ferrite aluminate cement (FAC) could rapidly lose fluidity or workability due to its excessive hydration rate, and greatly reduce the construction performance. Chemical admixtures are commonly used to provide the workability of cement-based materials. In this study, to ensure required fluidity of FAC, chemically different water reducing agents are incorporated into the FAC pastes. The experiments are performed with aliphatic water reducing agent (AP), polycarboxylic acid water reducing agent (PC) and melamine water reducing agent (MA), respectively. Influence of the water reducing agents on fluidity, setting time, hydration process, hydration product and zeta potential of the fresh cement pastes is investigated. The results show that PC has a better dispersion capacity compared to AP and MA. Besides decreasing water dosage, PC also acts as a retarder, significantly increasing the setting times, delaying the hydration rate and leading to less ettringite in the hydration process of FAC particles. The water reducing agents molecules are adsorbed on the surface of positively charged minerals and hydration products, however, for PC, steric hindrance from the long side chain of PC plays a critical role in dispersing cement particles, whereas AP and MA acting through an electrostatic repulsion force.

Sign in / Sign up

Export Citation Format

Share Document