High sulfide pyrite pellet reinforced roasting consolidation technology

Abstract

The invention discloses a high sulfide pyrite pellet reinforced roasting consolidation technology. Pellets are produced by adopting the technology of drying grate--rotary kiln--ring type refrigeration machine--flue gas desulphurization. The basic flow is as follows: prebatching--mixing--high press roll grinding--batching--mixing--pelletizing--drying--preheating--roasting--cooling--finished product output--flue gas desulphurization. From the perspectives of the occurrence state of sulfur in raw materials, the decomposition behavior of sulfur during the heating process, the iron ore pellet forming theory and the iron ore pellet consolidation mechanism, the system integration reinforced high sulfide pyrite pellet forming and pellet consolidating technology, which includes the improvement of pyritic slag pellet forming dynamics condition, the reinforcement of high sulfur pellet desulphurization and consolidation during the preheating and roasting processes and the control of high SO2 concentration flue gas features and migration rules, is adopted to solve the roasting problem of high sulfide pyrite, make the sulfur content of the finished pellets and the pellet ore strength reach related technical requirements and basically prevent flue gas from corroding equipment. The invention provides a new approach for effective utilization of high sulphur-containing iron concentrate and sulfuric acid slag resource.

Description

Technical field [0001] The invention relates to a process for roasting and consolidation of pellets, in particular to a process for enhanced roasting and consolidation of high-pyrite iron ore pellets. Background technique [0002] In recent years, with the rapid development of my country's pelletizing industry, iron ore concentrate resources at home and abroad are becoming increasingly scarce. The use of high-sulfur iron concentrate and sulfuric acid slag to produce iron ore pellets has attracted increasing attention. Generally, in the production of iron ore pellets, the sulfur content of the incoming raw materials is required to be as low as possible. When high-pyrite iron concentrate (S≥0.5%) is used to make pellets, there will be three technical problems in the oxidative roasting process. One is that sulfur in the form of sulfate is not easy to remove under conventional roasting atmosphere. ; Second, during the roasting process of high-sulfur green pellets, the oxidative rem...

AI Technical Summary

Problems solved by technology

When using high-sulfur iron concentrate (S ≥ 0.5%) to make pellets, there will be three technical difficulties in the oxidation roasting process. First, the sulfur element in the form of sulfate is not easy to remove under the conventional roasting atmosphere. ; Second, during the roasting process of high-sulfur green pellets, the oxidation and removal of sulfur will affect the oxidation, strength and consolidation speed of the pellets; third, the roasting flue gas of high-sulfur iron concentrate pellets will contain higher Concentration of SO 2 and SO 3 , the problem of dew point corrosion of low-temperature exhaust gas and the problem of flue gas desulfurization of large volumes are also difficult to solve

Therefore, the three problems existing in the roasting of high-sulfur iron concentrate pellets have always been the bottleneck restricting the diversification of pellet raw materials

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