Lead And Zinc Mine Huize Pit Inflow Forecast

The mining history of Huize lead-zinc mine is more than 50 years. The underground mining middle part is 1031m (Qilin Factory)-1584m (Kuangshan Factory) now. Previous hydrological and engineering geology work mainly above the 1571m (Qilin Factory)-1764m (Kuangshan Factory).As a typical water-filled fissured bedrock deposit, buried condition of water-filled fissure and hydrodynamic property are more uneven in Huize lead-zinc mine. After years of mining, hydro geological conditions of deep deposit has greatly changed. Now, the total water yield is about 12600m3/d. With the depth of exploitation increases, the water yield and the risk of water flush are increasing. At present ore can be mined is under the Niulan River which is the larger tributaries of the Jinsha River. The underground mining lead to mine hydro geological conditions and groundwater seepage field change and the risk that infiltration of surface water induces mine water gushing increase. Mine water gushing becomes the main factor which constraints deep mine mining. To ensure the security of future mining activities in the deep deposits, it is great significance to do a detailed hydro geological investigation and research, as well as numerical simulation of the deep mine water inflow forecasting.In this paper, based on the collation and analysis of hydro geological data have been collected; we conducted field investigations respectively in the dry season and in the wet season. Find out hydro geological conditions of mining and divide hydro geological units on the basis of dynamic characteristics of mine groundwater. Use GMS Groundwater Modeling System software simulate groundwater flow of mining area.Using the GMS simulation model analysis the influence of hydrogeology parameters such as permeability coefficient, water coefficient, planar supplies to the mine water gushing. Using modflow model which has adjusted parameters simulate water yield at different depth in the mining area and evolution characteristics of seepage over time. By numerical simulation studies, we get the key factors which impact on the water yield of deep mining middle part, and simulate the evolution characteristics of seepage field and water yield over time in the deep mine. The study obtained the following understanding:1. Permeability coefficient, water storage coefficient is the important factor of water inflow at deep mining condition in the future. 2. Huize lead-zinc mine basically belongs to the first subclass of water-filled karst deposit-corrosion fissure based water-filled karst deposits. The main aquifers are D3zg, C1d and C1b, and Cib is main ore-bearing layer.3. The mainly factors that affect the deposits water-filled are atmosphere precipitation intensity, degree of crack development, stratigraphic occurrence and terrain conditions. Terrain height and the steep of terrain slope determines the size of surface water recharge on the deposits water filling; atmospheric precipitation is the main recharge source for sap groundwater; structural cracks and fissures between layers is the main Channels of groundwater flow, and it controls the variation of groundwater seepage field; while deposit mine dewatering pumping is a major drainage way in deep groundwater discharge.4. After a long-term dynamic observation of groundwater in more than one year in the mining area, the results show that groundwater static reserves is the main resource to deep mine water gushing. With the depth of exploitation deeper, the pressure of groundwater becomes higher. Pay attention to short-term water flush and water inrush phenomenon in the exposing rich water segment.5. Appling the corrected Modflow numerical simulation model to simulation seepage field features variation of groundwater under different mining water inflow conditions of the area, The results showed that:with the pumping and drainage of exploitation time prolonged, the seepage field of deep exploitation center-sections which have expose the aquifers will formation a deep landing funnel. And the water inflow of some part of the tunnel will gradually have been dewatering due to limited sources of supply.