The reverberatories are usually not tapped until they contain about 250 tons of matte. The operation of tapping is performed by withdrawing the rod by means of a wedge and ring, when the matte flows along the launders leading to the ladles for the converters; two ladles of about 8 tons capacity each are usually filled at once, each ladleful being sampled at the runner. The tap-hole is then stopped with a cone of clay, and the tapping-rod driven through it again.
Typical daily reports of the furnaces are appended in Tables VI. and VII., and a monthly report on Table VIII.
TABLE VII.—From Daily Assay Report—Reverberatory Furnaces.
August 19, 1908.
| Furnace Number. | Per Cent Copper in Slag. | ||
|---|---|---|---|
| Shift 1. | Shift 2. | Shift 3. | |
| 1 | 0·30 | 0·30 | 0·30 |
| 2 | 0·30 | 0·35 | 0·25 |
| 3 | 0·30 | 0·30 | 0·35 |
| 4 | 0·45 | 0·30 | 0·25 |
| 5 | 0·30 | 0·40 | 0·35 |
| 6 | 0·30 | 0·20 | 0·20 |
| 7 | .. | .. | .. |
| 8 | 0·35 | 0·25 | 0·30 |
| Average in slag, | 0·35 | 0·30 | 0·30 |
| Composition of calcines |  | SiO2, | 29·5 | per cent. |
| FeO, | 37·3 | " | ||
| S, | 7·7 | " | ||
| CaO, | 2·7 | " | ||
| Copper, | 8·6 | " | ||
Composition of slag, |  | SiO2, | 39·4 | per cent. |
| FeO, | 40·7 | " | ||
| CaO, | 4·3 | " | ||
Copper in matte, | 38·6 | " |
TABLE VIII.—Monthly Report—Reverberatory Furnaces.
Total Charge—All Furnaces.
| Charge. | SiO2. | FeO. | |||
|---|---|---|---|---|---|
| Tons. | Per cent. | Tons. | Per cent. | Tons. | |
| Calcines and lime rock | 50,054 | 27·20 | 13,616 | 39·40 | 19,721 |
| M‘Dougal flue-dust, | 977 | 30·50 | 298 | 21·90 | 214 |
| Blast flue-dust, | 1,639 | 35·90 | 588 | 22·00 | 361 |
| Converter flue-dust, | 132 | 1·90 | 2 | 6·60 | 9 |
| Main flue-dust, | 1,034 | 30·2 | 312 | 17·80 | 184 |
| Total, | 53,836 | .. | 14,816 | .. | 20,489 |
| Matte to converter, | 10,950 | .. | .. | 36·70 | 4,019 |
| Matte chips to B.F., | 74 | 8·20 | 6 | 38·10 | 28 |
| Slag chips to B.F., | 609 | 39·50 | 241 | 37·40 | 228 |
| Deduct from above total, | 11,633 | .. | 247 | .. | 4,275 |
| Leaves for slag, | .. | .. | 14,569 | .. | 16,214 |
| Lime. | Sulphur. | Copper. | ||||
|---|---|---|---|---|---|---|
| Per cent. | Tons. | Per cent. | Tons. | Per cent. | Lbs. | |
| Calcines and lime rock, | 2·30 | 1,150 | 8·40 | 4,205 | 8·266 | 8,274,799 |
| M‘Dougal flue-dust, | 1·30 | 13 | 14·00 | 137 | 7·884 | 152,295 |
| Blast flue-dust, | 4·30 | 70 | 6·70 | 110 | 5·698 | 186,782 |
| Converter flue-dust, | .. | .. | 12·10 | 16 | 68·743 | 181,482 |
| Main flue-dust, | 2·10 | 22 | 8·80 | 90 | 7·128 | 147,405 |
| Total, | .. | 1,256 | .. | 4,558 | 8·305 | 8,942,763 |
| Matte to converter, | .. | .. | 26·40 | 2,891 | 38·209 | 8,367,872 |
| Matte chips to B.F., | 0·20 | .. | 21·80 | 16 | 32·811 | 48,560 |
| Slag chips to B.F., | 2·30 | 14 | 2·20 | 13 | 35·597 | 43,357 |
| Deduct from above total, | .. | 14 | .. | 2,920 | .. | 8,459,789 |
| Leaves for slag, | .. | 1,242 | .. | .. | .. | .. |
| Analysis. | ||||
 | ||||
| Slag Calculation─ | Calculated. | Actual. | ||
| SiO2 | in slag, | 14,569 ÷ 38,538 | 37·8 | 37·1 |
| FeO | " | 16,214 ÷ 38,538 | 42·1 | 43·2 |
| CaO | " | 1,242 ÷ 38,538 | 3·2 | 2·8 |
| ——————— | ——— | ——— | ||
| 32,025 at 83·17 = 38,538 | 83·10 | 83·10 | ||
| ══════════ | ════ | ════ | ||