Surda Copper Mine Blasting Accident

Surda is located in East Singhbhum District of Jharkhand and is about 4 km south of Musabani. Jamshedpur, the district headquarters, is about 50 km north of Surda. Surda is noted for its copper mines. Ranchi Airport is the nearest airport. Ghatsila Railway Station (15 km) is the nearest railway station.

This accident occurred in No.10 level stope which was worked by the “post-pillar method”. The method of stoping comprised horizontal slicing over a strike distance of about 80 m upto the full width of the ore-body leaving 4 m square vertical posts in-situ at intervals of 13 m along the strike direction and 9 m across the ore-body. The void thereafter was hydraulically stowed solidly with mill tailings. Slicing was started from the lower level after leaving a 10 m thick sill pillar and it continued upto the upper level. The rock was hard and blasting invariably produced boulders which needed secondary blasting. ANFO was used for “plaster- shooting” to break the boulders. A cartridge of special gelatine was used as booster for ANFO.

On 4.4.1984 by about 9 p.m., 80 boulders had been charged for plaster shooting in the 10 level stope. All the 80 shots were fired simultaneously electrically from No.9 level which, was the return airway for the 10 level stope. The mate, the blaster, his helper and four drillers of No.9 level stope, remained ion No.9 level. After blasting at 9.30 p.m., the mate, the blaster, his helper and two drillers, tried to reach No.9 level sub-incline platform but a ventilation door on the way was found jammed due to the shock wave of blasting. In the meantime, electric power failed resulting in stoppage of the fan. These people retraced their steps passing through an atmosphere laden with blasting fumes. They then contacted No.10 level sub-incline on telephone. The mate of No.10 level development district came along with a few more persons and opened the offending ventilation door. Then the seven persons inbye of the door came to No.9 level sub- incline at 10.05 p.m. Three of them (the blaster, his helper and one driller) were feeling uneasy. They were sent to the hospital at Mosaboni at 11 p.m. The mate did not feel much discomfort and went to his residence. But after some time he felt difficulty in breathing and was brought to the hospital at about mid-night. All these four patients initially had severe headache, uneasiness, irritation in the chest and slight breathing difficulty. In 2 hours their condition deteriorated and all of them died between 2.30 and 3.30 a.m. on 5.4.1984, that is, within 6 hours of their being affected by blasting fumes. Another driller had gone to bed after taking his dinner. After a few hours he also complained of difficulty in breathing. He was taken to the hospital at 5. I 0 a.m. but expired within 10 minutes.

Investigations under simulated conditions indicated that immediately after blasting, the concentration of nitrous oxides in the atmosphere near the, offending door exceeded 100 p.p.m. It was the exposure to such high concentration of oxides of nitrogen which led to the death of five persons.