AP19579175 – «Investigation of the selective reduction of iron by hydrogen gas from oolitic ores with a high phosphorus content»

The largest share of steel is produced by the reduction of iron oxides with carbon, which leads to the reproduction of anthropogenic CO2 emissions, which account for ≈ 30% of all industrial CO2 emissions. These numbers qualify manufacturing as a nationwide major cause of global warming and pose an urgent problem of decarbonisation. Throughout the steel chain, the production of iron ore reduction in blast furnaces with carbon up to 80-90% is within CO2.

In connection with the increase in steel production, iron ore deposits are involved in production, which have an increasingly complex mineralogical composition, as well as with an increased content of phosphorus (0.4-1.8%), in particular, oolitic ores, which are widely distributed in the form of quite large deposits. In the Republic of Kazakhstan, oolitic ores make up the bulk of the recorded iron ore reserves, more than 60% of which are concentrated in the Lisakovskoye, Ayatskoye, Kokbulak, Kutanbulak and Taldyespe deposits.

It is difficult to reduce the phosphorus content in the ore using traditional enrichment methods, since the phases of iron oxide and gangue are tightly bound, and they are difficult to dissociate. During the process of recovery of high-phosphorus ore in a blast furnace, almost all of the phosphorus will be transferred to pig iron, which will further lead to an increase in the volume of slag and loss of electricity during steelmaking. Thus, the dephosphorization of high-phosphorus iron ores is the most important stage in the processing of these ores.

It is proposed to carry out the process of gas-phase selective reduction of iron, in order to separate iron and phosphorus, with the production of a metallized material. Hydrogen is used to implement the selective reduction of iron without phosphorus. The issues of the use of hydrogen in metallurgy currently continue to gain relevance due to the need to reduce the burden on the environment from iron metallurgy.

1) Yerzhanov Almas – Doctor of Philosophy (PhD), associate professor, project leader.

Scopus ID: 56524559600

Researcher ID: AFL-9951-2022

https://orcid.org/0000-0002-8990-5919

2) Kuatbay Yerbol – Doctor of Philosophy (PhD), project executor.

Scopus ID: 57218196966  

Researcher ID: ABE-5679-2021 

https://orcid.org/0000-0002-8400-3537

3) Zhuniskaliev Talgat – Doctor of Philosophy (PhD), senior researcher at the Department of Science, Innovation and International Cooperation, project executo.

Scopus ID: 57218196497  

Researcher ID: AAG-6131-2021  

https://orcid.org/0000-0001-9757-0605

4) Gamov Pavel – candidate of technical sciences, associate professor.

Scopus ID: 55618981700

https://orcid.org/0000-0002-1474-644X

5) Suleimen Bakyt – researcher at the Department of Science, Innovation and International Cooperation, project executor.

Scopus ID: 57215054180

https://orcid.org/0000-0001-9306-1045

6) Kosdauletov Nurlybay – researcher at the Department of Science, Innovation and International Cooperation, project executor.

Scopus ID: 57215058827

https://orcid.org/0000-0002-1570-4188

7) Adilov Galymzhan – researcher at the Department of Science, Innovation and International Cooperation, project executor.

Scopus ID: 57213596057

Researcher ID: ABL-6521-2022

https://orcid.org/0000-0002-1012-8097

8) Abdirashit Asylbek – Master of Technical Sciences, project executor.

Scopus ID: 57218196252

Researcher ID: ABE-5588-2021

https://orcid.org/0000-0003-0718-3041

During the implementation of the project, it will be shown that the use of selective solid-phase reduction in pyrometallurgical processes makes it possible to expand the raw material base of the ferrous metallurgy of Kazakhstan. The implementation of this project will provide an opportunity to comprehensively study the chemical and phase transformations of the components of oolitic iron ore. As a result, new theoretical and experimental data on the distribution of iron and phosphorus during reduction roasting will be obtained, and an assessment of the efficiency of dephosphorization and the possibility of its use in existing processes will also be given.

The possibility of practical use of the expected results of the project in the economy, including for the creation of new applied technologies, is assessed by the fact that on the basis of the results obtained, the optimal parameters of reduction roasting (time, temperature, composition of the gas phase) and the optimal parameters of separative melting (time, temperature, composition of the slag phase), which can be used in the development of technology for producing steel from oolitic ores using modern coke-free technologies to obtain phosphorus-free steel.

The environmental impact of the project will be the use of hydrogen gas to directly reduce iron from ore, which will significantly reduce massive anthropogenic CO2 emissions from the steel industry.

The scientific and technical effectiveness of the project is aimed at solving the national project of the Republic of Kazakhstan “Technological breakthrough through digitalization, science and innovation” and at improving the production of high-quality metal products.

The results of scientific research will be published at international conferences, as well as in peer-reviewed foreign or domestic publications recommended by the CQASHE in this area and therefore will be available to scientists. The test results will be validated and recommended to production organizations for the implementation of the technology for the complex processing of high-phosphorus oolitic iron ore using solid-phase selective reduction of iron with hydrogen-based gases and with further pyrometallurgical separation to obtain metallic iron and phosphorus slag.

1) Currently, the most relevant direction for processing high-phosphorus oolitic ores is the use of hydrogen as a reducing agent for the selective reduction of iron. The development and implementation of breakthrough technology for the use of hydrogen as a reducing agent in ferrous metallurgy on an industrial scale will make it possible to involve complex, low-grade and complex ores in the production. To study the mineralogical composition of the original ore, X-ray phase analysis (XPA) was performed on a Rigaku Ultima IV diffractometer. According to the XRF results, the main phases of the original oolitic ore of the Lisakovsky deposit are goethite (FeO(OH)), magnetite (Fe3O4) and quartz (SiO2), in addition, iron, calcium and magnesium carbonates are detected. Phosphorus in the original ore is contained in the form of iron hydrogen phosphates (FePO4·2H2O) and calcium (CaHPO4·2H2О), as well as aluminum phosphate (AlPO4). When fired (1200℃) in an air atmosphere, goethite (FeO(OH)) loses water and turns into hematite (Fe2O3). Phosphorus in the calcination product is present in the form of compounds FePO5 and AlPO4. The elemental composition of the original and roasted ore was determined by micro-X-ray spectral analysis using a Jeol JSM-7001F scanning electron microscope. It was revealed that the original and roasted ore contains the elements Mg, Al, Si, P, Ca, Ti, Cr, Mn, Fe, Co, Ni, Zr. After oxidative firing, oolites are not destroyed, they also have a round shape, but small cracks appear in them.

2) XRF on the basis of Lisakov ken ornynyn bastapky oolite keninin negіzgі phasalary goethite (FeO(OH)), magnetite (Fe3O4) and quartz (SiO2) large tabyldy, sonomen qatar temir, calcium and magnesium carbonattars ana ktaldy. Phosphorus bastapky kende temir hydrophosphates (FePO4 2H2O) and calcium hydrophosphates (CaHPO4 2H2O), and aluminum phosphates (AlPO4) are also important. Aua atmospheresynda kuydiru kezinde (1200°) goethite (FeO(OH)) courts jogaltada zane hematite (Fe2O3) aynalada. Phosphorus is combined with FePO5 and AlPO4 for the most part. Bastapky zhane kuydirilgen kenderdin elementtik karama Jeol JSM-7001F scannerleash electrons microscope microroentgen spectraldyk taldau adіsіmen anyktaldy. Bastapky zhane kuydirilgen ken Mg, Al, Si, P, Ca, Ti, Cr, Mn, Fe, Co, Ni, Zr elementerinen turatyny anyktaldy. Totyktyryp kuydirgennenen keyin ooliter buzylmaidy, salt doңgelek pіshіndі bolada, take olard azdan zharyktar paida bolada.