Mohave County miner., 1918-03-16
CORRESPONDENT DESCRIBES
 HUMBOLT SHELTER PLANT

sticky material to keep a man in the bin being drawn even though the slope is steep and the chutes fitted with apron feeders.
 All direct smelting ore received into the plant, both from the company's mines and from outside mines is de- livered in railroad cars over the 12 re- ceiving bins which have a combined capacity of 2O0O tons.
 The blast furnace is charged alter nately from either side using Anacon- da type charge cars tilted by air hoists. A charge consists of 10000 pounds of ore, limerock and converter slag skulls with Il per cent coke. The blast pressure is 26 ounces and the furnace smelts 300 tons of charge per day.
 Conveyor belts running under the fire ore bins and concentrates bins pick up the feed for the roaster plant. The belts carry the feed to the top of the roaster building where it is dis charged by tripper into the storage bins, one above each of the four roast CTS. Each bin has a capacity of 125 tons.
 The dust-laden gases from the roast CTS are passed through Cottrell cleo tric precipitation treaters located above the roasters. There is no set ting chamber, the gases going direct ly to the treaters.
 The dust precipitation takes place as follows: The solid particles car ried by the gases passing upwards through the tubes are electrified with charge of like sign as the chain, and are drawn to the tube. In like man. ner a small portion of the particles are charged by the tube and drawn to the chain. A rapping device is pro vided to jar the particles loose from the tubed and chains. The feed par ticles drop in a mass to the hoppers beneath the tubes. From these hop pers the rust is conveyed by 10-inch helicoil conveyor to the end of the building where it drops through a chute into a firebrick lined hopper at the bottom of the building. A similar hopper, of IS tons capacity, receives the calcines from each roaster. These hoppers discharge into standard gauge calcine cars carrying the cal cines to the reverberatory furnace 250 feet distant.
 The reverberatory furnace (9x100 feet) treats 250 to 300 tons per day of dry solid charge, of which 75 per cent is hot calcines and the balance free. ores used for fettling. The fur mace also receives all the molten con- verter slag. Nearly all the charge i'd dropped from overhead hoppers along the sides of the furnace. Cal ifornia crude oil, IA degrees Baume, is used for fuel Back of the fur naces are two 25O-h. p. Stirling water tube boilers utilizing the heat in the waste furnace gases for the produc- tion of steam. Enough steam is gen erated by waste heat to run the con- verter blowing engine with some slight excess for other purposes. Most of the power used generally through out the plant and at the mines1 hoy ever, is hydro-electric power purchas- ed from the Arizona Power company.
 The blast furnace and reverbera- tory mates each average 35 per cent copper. Two 30-ton cranes serve the three ' 1-2 feet by 10 feet converters, two of which are kept in the stack continuously producing about 1,8O0,- 900 pounds copper per month. The converters are of the old acid lining type though now operated with basic lining. Their work is not very satis- factory, however, and makes for high costs in labor and Innings. It is hoped that within the year they can be re- placed with one or more larger and