Stoppings to seal-off abandoned mine workings - by pumping mix between support walls with specified binder to filter ash ratio

摘要

Stoppings to seal off abandoned mine workings are produced by injections of a pumpable mix formed from cement, electro-filter ash as filler and water in between pre-erected support walls. Binder and filter ash are admixed in a ratio of 1:7-8. - Stoppings should be erected in this sequence. The cement and filter ash mix should be transported by container to the mixing point below ground where the dry mix is fed by compressed air hose from container to a rotating compressed air mixer for mixing with water. The moist mix should then be pumped by air pump through hoses, preferably fire fighting hoses to the stopping site.