1 General Provisions
1.0.1 This code is formulated with a view to standardizing the technical requirements for waste dump design of nonferrous metal mines, implementing the national technical and economic policies, as well as reaching the requirement of safely stockpiling mine overburden and protecting the environment.
1.0.2 This code is applicable to the design of newly-built, renovated and extended waste dump of nonferrous metal open-cut mine and underground mine.
1.0.3 Waste dump design shall meet the following requirements:
1 Meet the general planning of mine construction; to-be-built site and waste disposal process must achieve safety and reliability, advanced technology as well as economic rationality.
2 Multiple-scheme economic and technical comparison shall be carried out for the site selection of waste dump. The economic criteria of the optimal scheme: the present value of waste rock transportation, dumping, environmental pollution regulation and reclamation costs converted into the unit ore cost is the minimum during the service life of mining.
3 Waste dump planning shall meet the full capacity of service life; combination of long-term and near-term shall be adopted for installation of waste dump; waste dump land can be expropriated by stage according to the waste disposal plan.
4 When the waste dump is designed, liability extent of environmental influence and soil erosion prevention and elimination shall be determined through site survey, adjusting measures to local conditions, insisting on the principles of giving priority to prevention and combined prevention and elimination, as well as comprehensively implementing the national policies such as arable land protection, environmental protection, soil erosion prevention and elimination, land reclamation and sustainable development.
1.0.4 Except for those requirements stipulated in this code, those in the current relevant ones of the nation also shall be complied with for the design of waste dump.
2 Terms
2.0.1 Waste dump; spoil dump
Waste dump is the place for heaping overburden, the place for dumping waste in mining.
2.0.2 Internal waste dump
Internal waste dump is the waste dump where the overburden is heaped in the goaf or subsidence area.
2.0.3 External waste dump
External waste dump is the waste dump where the overburden is heaped outside of the boundary of open mine.
2.0.4 Overburden
Overburden, also called waste rock or rock-soil, is the overburdened cladding rock-soil, surrounding rock, ore currently without utility value, and lost ore in exploitation.
2.0.5 Waste disposal
Waste disposal is the operation to discharge the overburden into the stockpiling site.
2.0.6 Subsidence factor of waste dump
Subsidence factor is the ratio of subsidence height to height of waste dump before subsidence.
2.0.7 Land reclamation
Land reclamation is the operation to treat, recover and transform the damaged land to the available state, during the waste disposal heaping process of waste dump.
2.0.8 Bench
Bench is also called stage. The overburden in the waste dump is divided into a certain height in general, and disposed and heaped by layer.
2.0.9 Caving zone
Caving zone is the scope from the goaf to the surface that may cause surface crack and subsidence.
2.0.10 Browline
Browline is the forward line of the waste dump side slope surface and bench top surface.
2.0.11 Stability analysis
Stability analysis is the comprehensive evaluation for the rock-soil related to the engineering to see whether it will appear excess deformation and damage.
2.0.12 Bench height
Bench height, also called stage height, is the vertical distance from the slope top line to the slope base line of the waste disposal bench.
2.0.13 Heap height
Heap height is the sum of each bench height.
2.0.14 Safety factor
Safety factor is the ratio of anti-sliding force and sliding force, or the ratio of anti-sliding moment and sliding moment.
2.0.15 Reclamation period of waste dump
Reclamation period of waste dump is the time from the completion of waste disposal to the completion of reclamation.
3 Site Selection
3.1 General Requirements
3.1.1 Site selection of waste dump must be carried out synchronously with the mining design. Distribution of excavation and overburden, excavation sequence, as well as overburden amount shall be considered during the site selection. The waste dump site should be close to the stope.
3.1.2 Waste dump capacity shall be able to hold all the rock-soil dumped during the mine service life; waste dump site can be one or several. If it covers a large area at different time, the waste dump should be planned at a time, expropriated or rented by stage. When the land is expropriated at the preliminary stage, large-sized mine should not be less than 10 years' capacity; medium-sized mine should not be less than 7 years' capacity; small-sized mine should not be less than 5 years' capacity.
3.1.3 Separate dumping and separate heaping shall be carried out as required for the rock-soil and earth soil waste dump with recycling value, and favorable conditions shall be created for its recycling.
3.1.4 Relative merits of waste dump design scheme as well as design technology and economy shall be compared in the feasibility study and preliminary design documents, and shall include the following contents:
1 Dumping soil and stone quantity;
2 Dumping process and transportation distance;
3 Site scheme of waste dump;
4 Original geomorphic features, environmental factors and land occupation profile;
5 Area of occupied arable land and damaged forest;
6 Technical assurances of safety measures and protected zone;
7 Potential environmental protection problems and soil erosion hazard;
8 Reclamation arrangement.
3.1.5 Site scheme comparison of waste dump shall include the following contents:
1 Topography, engineering geology and hydrologic geology of site;
2 Natural conditions;
3 Transportation means, transportation distance, capacity and land of waste;
4 Recycling conditions for temporarily unavailable resources;
5 Safety and sanitation protection distance.
