Learning Factory - Sponsors - Examples of Past Projects

Semester: Fall 2011

Sponsor: Consol Energy, Inc.

Title: Electromagnetic hydrocyclone for magnetite recovery during coal benefication

Description: Process Opportunity: Increase the safety and efficiency of magnetite recovery equipment currently used in heavy media based coal beneficiation processes. Current Process Technology: During the coal cleaning process, waste rock is separated from coal using a media that has a density between that of rock and coal. One media that is commonly used in coal cleaning is a suspension of finely-ground ferrous solids in water. This media can be easily adjusted in density, and the majority of the ferrous solids can be recovered and recycled using magnetic devices. Magnetite (an iron ore) is usually the ferrous material of choice due to its resistance to oxidation, high bulk density, and commercial availability. In the last ten year period, process grade magnetite has more than tripled in price. The current magnetic separator technology uses rare-earth magnets exposed to a large surface area in extracting the magnetite from the aqueous suspension. Key Objectives: A more-effective magnetite recovery system will allow tighter control of the media density, resulting in higher process efficiency, and will reduce magnetite losses. Other benefits compared with existing magnetic separators are a small footprint, no moving parts and no stored energy sources. A successful design will consider the safety aspects, capital and operating cost improvements, and the practical application within the entire system. From the Spring 2011 Learning Factory Project, the team of students determined that coupling the centrifugal force of a cyclone with a pulsating electromagnetic field, a strong impetus to pull the magnetic particles from the suspension is created. The new project team will continue with this model and improve upon the design, in an effort to achieve or outperform the industry standard for magnetite recovery. Expected Project Agenda: Build upon the previous work done in the Learning Factory Spring 2011 Identify the governing scientific principles that will enhance the pilot unit’s performance Field trip to operating Coal Processing Plant Formulate the design and operating changes Modify the pilot unit to achieve industry standard or better magnetite recovery Sampling and analysis of the modified unit Evaluate the achievement of the goals