The Senate Appropriations Committee yesterday gave initial approval to a bill that would protect Western mining interests from tougher environmental rules proposed by the Interior Department. A 1997 Interior Department ruling limited the acreage of mining sites on federal lands, but this bill would exempt hundreds of mining operations from the ruling. Earlier this year, under pressure from Sen. Slade Gorton (R-Wash.), the Senate voted and Pres. Clinton approved a provision that exempted a large Washington state mine from the same ruling. The committee bill, which funds the Interior Department, would also cut about 40 percent from the administration’s request of funding for a land-legacy program, the Land and Water Conservation Fund.