Particle size controllable jet milling technology for efficiently recycling titanium-bearing blast furnace slag: Numerical simulation and industrial test.

Large amounts of titanium-bearing blast furnace slag have been dumped in China, resulting in serious environmental contamination and a waste of precious titanium resource. At present, a process for recovering titanium from titanium-bearing blast furnace slag has been developed. Unfortunately, current size reduction techniques fail to meet the material size requirements. In this paper, a particle size controllable jet milling technology was proposed based on the idea of one-time collision between the particle and the target. To better control the breakage size, computational fluid dynamics was used to model the new jet mill giving a detailed understanding of the mechanisms. Simulated results showed that the acceleration region of the low velocity fluid was located inside the ejected stream. The velocity at which the fluid hits the target was relatively uniform. It indicated that the new jet mill was advantageous for obtaining a pulverized product having a narrower particle size distribution. Experimental results showed that the excessive size reduction was effectively reduced. The average mass fraction of the particles with the particle size of <30 μm was 19.0%, 30–150 μm was 72.8%, and >150 μm was 8.2%, meeting the requirement for titanium recycling from titanium-bearing blast furnace slag in industry. This study provides a feasible method for reducing particle size to a desired distribution to promote resource sustainable utilization and pollution reduction in an environmentally friendly way. Image 1069 • Particle size control is first identified as the key to Ti-BFS recycling. • One-time collision concept is put forward to control particle size of fracture. • Particle size controllable jet milling system is proposed and established. • Ti-BFS is crushed to the desired particle size distribution. [ABSTRACT FROM AUTHOR]