Simulation of thermal processes of shaft plasma furnace for waste gasification

Mathematical modeling of a part of a mine plasma electric furnace for waste gasification is presented. In model calculations, the study of the effect of additional resistive heating as an in-furnace process of drying waste was carried out. In the course of modeling, the electrical resistance of the waste at natural moisture was taken into account. A study was carried out to identify the uniform release of energy inside the waste batch in the drying zone with different connections of the electrodes and the type of current.

Brazing of Porous Copper Foam with Copper Sheet Using CuNiSnP Amorphous Filler Metal

This research studies effects of the brazing time on interfacial microstructure of brazed joint between the porous copper foam (PCF) and Cu substrate using CuNiSnP amorphous filler metal. To examine the interfacial microstructure and its properties, an assessment of PCF/CuNiSnP/Cu brazed joints was conducted after electric furnace brazing under hydrogen (H2) atmosphere. The results showed that the interfacial microstructure was thick for short brazing time specimens and thin for prolonged brazing time specimens. The interfacial microstructures consisted of Cu-rich solid solution, (Cu, Ni)3P, and Cu3P as a eutectic structure discovered in the brazing region at different brazing times of 5, 10, and 20 min. Only the Cu-rich solid solution and (Cu, Ni)3P were found in the specimen with brazing time of 30 min. indicating that different brazing times affected interfacial microstructures and therefore reliability of the brazed joints.

Assessment of economic, energy and ecological efficiency of iron and steel production from orecoal briquettes in electric-furnace melting facility with application of hydrogen fuel

According to the Russia National cadastre, emissions of carbon dioxide in the steel industry in 2019 in the sector “Industrial emissions” accounted for near 50% of the whole volume of its emissions in the whole country’s industry. A perspective way to decrease emissions of greenhouse gases is application of hydrogen in technological processes of metallurgical stuff production. A brief characteristic of basic technologies of hydrogen production presented. Concept of hydrogen technology development in steel industry of Russia stated, basic directions of metallurgical subindustries restructing related to implementation of the new fuel – “brown” hydrogen presented. Possibilities of “brown” hydrogen obtaining as a secondary energy resource of metallurgical production considered. Results of calculation of economic, energy and ecological effectiveness of cast iron, steel and “brown” hydrogen production in electric-furnace melting facilities of new type presented. It was shown that replacement of scheme “blast furnace-basic oxygen furnace”, including production of sinter and coke, by electric-furnace melting production with obtaining hot metal and steel from ore-coal briquettes and application of “brown” hydrogen and recycling of carbon dioxide enables to exclude greenhouse gases emissions. Capital investment into the hydrogen project of 1.0 million t/year capacity with restructing production capacities will account for 9.5 billion Rubles (120.0 million euro), economical effect – 5.4 billion Rubles (70.0 million euro), period of capital investments payback – 1.8 year.

Tinjauan teknologi proses ekstraksi bijih nikel laterit

Bijih nikel laterit merupakan mineral yang mengandung senyawa oksida besi-nikel. Teknologi pengolahan nikel laterit secara umum ada 3 metode yaitu hidrometalurgi, pirometalurgi dan reduksi selektif. Hidrometalurgi merupakan metode yang menggunakan pelindian dan larutan seperti asam untuk mengekstraksi nikel laterit. Metode dengan pelindian asam yang bertekanan adalah metode yang paling optimal untuk mendapatkan nikel dengan grade dan recovery tertinggi. Akan tetapi metode ini memiliki dampak pencemaran lingkungan akibat hasil proses pelindian dan waktu yang lama. Metode yang kedua, yaitu pirometalurgi menggunakan temperatur tinggi sampai 1600°C sehingga membutuhkan banyak energi seperti proses blast furnace. Metode dengan rotary kiln-electric furnace merupakan metode optimal dalam pengembangan nikel laterit. Akan tetapi kekurangannya yaitu tanpa pemisahan pengotor, energi yang besar, serta masih ada permasalahan teknis seperti adanya material yang mengalami melt partial. Metode yang ketiga yaitu reduksi selektif merupakan proses pemisahan dengan menyeleksi terbentuknya besi oksida sehingga mendapatkan kadar nikel yang tinggi tanpa energi yang tinggi. Hal ini disebabkan adanya penambahan aditif untuk menghambat terbentuknya besi dan menurunkan temperatur reduksi. Metode ini sebagai alternatif pengolahan bijih nikel laterit jenis limonit dan saprolit menjadi konsentrat nikel dengan kadar nikel di atas 5 %.

Substantiation of refractory lining influence on the electric furnace efficiency for the production of ferronickel

Purpose. The purpose of the research is to substantiate the possibility of replacing existing MgO bricks with the MgO-C bricks due to their resistance to the slag aggressiveness of the electric furnace and the Si content in the resulting metal, which can have a positive effect on reducing the consumption of refractory materials. Methods. This research will be presented as the results of theoretical and experimental data determining the dependence of the electric furnace on the type of refractory material, walls construction, operating parameters and the electric furnace lining, that are expected to have a major impact on the cost output of production process. Findings. Based on the presented results, it has been revealed that MgO-C bricks are more effective in terms of preventing the furnace damage depending on refractory materials. Therefore, to optimize the production process, it is recommended to improve the composition of melted metal and slag, as well as to strengthen the control of the process parameters. Originality. Laboratory analyses are conducted in specialized laboratories, and the presented data have been obtained through the use of devices and equipment required for experimental research. Practical implications. The refractory materials are one of the main indicators of technical performance and production costs at NewCo Ferronickel in Kosovo. Therefore, the higher performance of the refractory lining will have a positive effect on the furnace durability and the quality of the final product.