| 摘要 |
<p>ACl-3 GRANULAR ACTIVATED CARBON MANUFACTURE FROM LOW RANK BITUMINOUS COAL LEACHED WITH DILUTE INORGANIC ACID Granular activated carbon is manufactured from low rank bituminous coal by crushing and screening the as received coal to produce 8/30 mesh granules, which are treated by leaching with a dilute aqueous solution of inorganic acid (H2SO4, H3P04, or HCl) at a concentration of about 13% by weight and at an aqueous solution to coal ratio of about 10/1 by weight, by washing off the acid, by drying thoroughly and by mixing with about 10% by weight of coal tar pitch. The so treated granules are ground to at least 65% by weight -325 mesh powder, which is compressed into pellets of 0.5" diameter and 0.5" long under a pressure of 40,000 to 80,000 psi, and then granulated to obtain 6/20 mesh granules. These granules are first charred by heating to 250.degree.C. at 150.degree.C./hour in an atmosphere of air and nitrogen and by maintaining the temperature for 4 hours, next devolatilized by heating to 450.degree.C. at 300.degree.C./hour in an atmosphere of N2 and the volatiles and by maintaining the temperature for 1 hour, and then activated by heating to 800 to 900.degree.C. in an atmosphere of N2 and steam and by maintaining the temperature for 4 to 5 hours. The activated granules have a surface area of 1050 to 1090 m2/gram, an iodine number of 900 to 1100, an ash content of 6 to 9%, an abrasion number of 75 to 80, and an apparent density of 0.51 to 0.53 gram/cc, which properties make them suitable for use in waste water treatment and other applications.</p> |
