我矿矿脉走向大致平行,圍岩为黑云母片麻岩,矿脉厚平均5米左右:傾角30～34°。矿石普氏系数f=8～10,松散系数为1.73。云母的分布規律有两种:一种呈稳定的层状,富集于靠近頂板,其厚为0.3～0.5米;一种呈浸染状,分布于偉晶岩脉中,一般在岩脉的上部或中部,云母賦存較富。我們过去用土法开采,即采用“坑道采矿法”,矿硐多开掘于岩脉內诖笤窘?我們改革了采矿法,采用选別分层充填采矿法。以后根据我矿地质情况,又改用水平分层充填采矿法。实踐証明,这一种采矿法有如下优点: 1.自由面多,可以大大提高爆破效率。如 The direction of the ore veins of our mine is generally parallel, and the surrounding rocks are biotite gneiss. The average thickness of the veins is about 5 meters: the dip angle is 30 to 34 degrees. The ore’s Platts’ coefficient is f=8~10, and the loose coefficient is 1.73. There are two kinds of distribution rules of mica: one is a stable layer, which is enriched in the vicinity of the roof, and its thickness is 0.3 to 0.5 meters; one is disseminated and distributed in pegmatite veins, generally in the upper part of the dyke. Or in the middle, mica is richer. In the past, we used the earth method for mining, that is, using the “pilot mining method”. The mines were dug in the veins of the rock. We have reformed the mining method and adopted the selective layered filling mining method. Later, based on the geological conditions of our mine, it was changed to horizontal stratified filling mining method. Practice has proved that this kind of mining method has the following advantages: 1. There are many free surfaces, which can greatly increase blasting efficiency. Such as