The effects of heat treatment on the magnetic properties of coals doped with metallic Ni

✍ Scribed by Osamu Ito; Ken Tsuchibe; Yasuo Ohtsuka; Masashi Iino

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 559 KB
• Volume: 27
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(89)90063-8

✦ Synopsis

The magnetic susceptibility and magnetic resonance spectroscopy of coals doped with Ni have been measured as a function of heat treatment temperature (HTT). Both the susceptibilities and magnetic resonance signals began increasing at H'lT of 300 to 500°C by a factor of lo\* to 103. The HTT corresponding to this steep increase shifted to higher temperatures with coal rank; 300°C for brown coal, 400°C for bituminous coal and 500°C for anthracite. With the changes in the magnetic properties, the state of aggregation of Ni particles in coals changed. From the parameters of magnetic resonance spectroscopy combined with x-ray diffraction data, it is presumed that ultrafine Ni particles (lOO A) were produced in the bituminous coal and anthracite.