Coke Recovery.—A constant stream of half-burnt fuel and ashes falls through the bars, and during the clinkering operations large quantities are dropped. The material all falls down a bank inclined at 45°, into a channel where it is met by a stream of water which washes it along launders and through a grizzle, to a settling tank. The settled products are subsequently jigged, the recovered coke being washed over the tail-board to a trommel, and by this means 10 per cent. of the fuel charged into the furnace is recovered in a useful form. This coke is used up as a constituent of the briquettes.
TABLE VI.—Daily Report—Reverberatory Furnaces.
August 17th, 1908 (Good Day).
| Charge. | ||||||||
|---|---|---|---|---|---|---|---|---|
| Furnace No. | Coal | Total Smelted | Calcines | Macdougal Flue-Dust | Blast Furnace Flue-Dust | Main Flue-Dust | Extras | Residues |
| Tons | Tons | Tons | Tons | Tons | Tons | Tons ‡ | Tons | |
| 1 | 60·6 | 288·8 | 279·2 | .. | 8·9 | .. | 0·7 | .. |
| 2 | 57·2 | 277·7 | 262·7 | .. | 2·9 | 11·8 | 0·3 | .. |
| 3 | 64·1 | 286·7 | 253·2 | 12·0 | 8·9 | 11·8 | 0·8 | .. |
| 4 | 60·5 | 278·7 | 264·7 | .. | 2·6 | 3·9 | 0·2 | 7·3 |
| 5 | 57·3 | 245·9 | 221·7 | 12·0 | 11·2 | .. | 1·0 | .. |
| 6 | 57·3 | 273·1 | 264·4 | .. | 7·9 | .. | 0·8 | .. |
| 7 | .. | .. | .. | .. | .. | .. | .. | .. |
| 8 | 57·4 | 278·7 | 266·8 | 11·9 | .. | .. | .. | .. |
| Total | 414·4 | 1929·6 | 1812·7 | 35·9 | 42·4 | 27·5 | 3·8 | 7·3 |
| ‡ = Fine lime rock. | ||||||||
| Delays. | ||||||||
|---|---|---|---|---|---|---|---|---|
| Furnace No. | Copper Material Smelted per Ton of Coal | Cost of Coal per Ton of Metal Melted | Waiting for Coal | Waiting for Calcines | Miscellaneous | Total Delays | Boilers Working | Ladles of Matte in Furnace at End of Day. |
| Tons | $ | Hours | Hours | Hours | Hours | Hours | ||
| 1 | 4·77 | 0·95 |  | —— No delays. —— |  | 24 | 10 | |
| 2 | 4·85 | 0·94 | 24 | 10 | ||||
| 3 | 4·47 | 1·02 | 24 | 10 | ||||
| 4 | 4·61 | 0·99 | 24 | 10 | ||||
| 5 | 4·29 | 1·06 | 24 | 10 | ||||
| 6 | 4·77 | 0·95 | 24 | 10 | ||||
| 7 | .. | .. | .. | .. | ||||
| 8 | 4·85 | 0·94 | 24 | 10 | ||||
| Total | .. | .. | .. | .. | .. | .. | 168 | 70 |
| Draft, 1·7 inches. | Number of furnaces running, | 7·00 |
| All furnaces working slow. | Number of charges, | 140 |
| Furnace No. 5, one bad charge. | Ladles matte tapped, | 34 |
| Cupriferous material smelted per furnace, 275·6 tons. | ||
| DAILY REPORT—REVERBERATORY FURNACES. AUGUST 19TH, 1908. | ||||||||
|---|---|---|---|---|---|---|---|---|
| Charge. | ||||||||
| Furnace No. | Coal | Total Smelted | Calcines | Macdougal Flue-Dust | Blast Furnace Flue-Dust | Main Flue-Dust | Extras | Residues |
| Tons | Tons | Tons | Tons | Tons | Tons | Tons | Tons | |
| 1 | 55·4 | 143·0 | 143·0 | .. | .. | .. | .. | .. |
| 2 | 55·4 | 246·4 | 240·1 | .. | .. | .. | .. | 6·3 |
| 3 | 62·1 | 250·7 | 236·9 | .. | .. | 13·8 | .. | .. |
| 4 | 58·9 | 262·7 | 262·9 | .. | .. | .. | .. | .. |
| 5 | 62·2 | 247·8 | 247·8 | .. | .. | .. | .. | .. |
| 6 | 59·1 | 241·9 | 241·9 | .. | .. | .. | .. | .. |
| 7 | .. | .. | .. | .. | .. | .. | .. | .. |
| 8 | 55·1 | 252·9 | 252·9 | .. | .. | .. | .. | .. |
| Total, | 408·2 | 1645·6 | 1625·5 | .. | .. | 13·8 | .. | 6·3 |
| Delays. | ||||||||
|---|---|---|---|---|---|---|---|---|
| Furnace No. | Copper Material Smelted per Ton of Coal | Cost of Coal per Ton of Metal Melted | Waiting for Coal | Waiting for Calcines | Miscellaneous | Total Delays | Boilers Working | Ladles of Matte in Furnace at End of Day. |
| Tons | $ | Hours | Hours | Hours | Hours | Hours | ||
| 1 | 2·58 | 1·76 | .. | .. | 8·00 | 8·00 | 22 | 2 |
| 2 | 4·45 | 1·02 | .. | .. | .. | .. | 24 | 8 |
| 3 | 4·04 | 1·13 | .. | .. | .. | .. | 24 | 6 |
| 4 | 4·46 | 1·02 | .. | .. | .. | .. | 24 | 6 |
| 5 | 3·98 | 1·14 | .. | .. | .. | .. | 24 | 8 |
| 6 | 4·09 | 1·11 | .. | .. | .. | .. | 24 | 8 |
| 7 | .. | .. | .. | .. | .. | .. | .. | .. |
| 8 | 4·59 | 1·19 | .. | .. | .. | .. | 24 | 8 |
| Total, | .. | .. | .. | .. | 8·00 | 8·00 | 166 | 46 |
| Draft, 1·7 inches. | Number of furnaces running, | 6·67 |
| Furnace No. 1 delayed 8 hours tapping and claying. | Number of charges, | 118 |
| Furnace No. 7 down for repairs. | Ladles matte tapped, | 47 |
| Bad coal on all furnaces. | Cupriferous material smelted per furnace, 246·7 tons. | |
Tapping the Furnace.—Matte is usually withdrawn from these large stores upon such occasions as it is required for the converters, though sometimes when the supply has got ahead of the converters’ demands, the matte is tapped and run outside the reverberatory building, being cast into large matte-beds. The tap-holes are situated between the second and third doors, and between the fourth and fifth; and each consists essentially of a copper plate 2 inches thick and 25 inches square, which at first stands back 9 inches from the outside of the wall. Through this plate a 1-inch hole has been drilled. The tapping bar is maintained inserted up this hole, being passed through the conical clay plug which closes it. At the back of the plate is 21 inches of lining material through which the tapping-hole passes. When the copper plate shows signs of a red heat, it is an indication of the lining tending to burn through; this part of the furnace is then cooled, the plate taken out, a 9-inch layer of sand is rammed into position, and the plate is thus moved forward a corresponding distance. Such a tap-hole plate lasts for about five months.