Cradle to Gate
Identity ID
6a87cdf0-3011-46b9-9a11-d9f101f8cece
Materials
Associated ID
cb6a31b5-bed3-4c48-aa02-bbe7f76cf2f1
Included activities starts
Included activities ends
Description
This dataset represents iron ore extracted from underground mines in Hebei. It covers a life cycle inventory cradle-to-gate, starting from drilling and ending with iron ore production, including all activities related to iron ore mining operations, but excluding the production of drilling rigs, transport equipment, personnel commuting, and direct or indirect greenhouse gas emissions from daily office operations during the mining production process. The dataset was compiled from multiple data sources based on national standards such as the 'Manual of Production and Emission Coefficients for the Iron Ore Mining and Processing Industry (0810)', 'Emission standard of pollutants for mining and mineral procressing industry (GB 28661-2012)', 'Cleaning production standard Iron ore mining and mineral processing industry', and 'The norm of the energy consumption per unit product of iron ore dressing(GB31337-2014)', and is representative of the average production level of iron ore mining using the shrinkage stoping method in Hebei.
Activity Description
This dataset describes the iron ore mining in Hebei using the shallow-hole shrinkage stoping method, with the following process steps:
1. Orebody exploration and drilling pattern design
Orebody exploration: Prior to mining, detailed geological exploration of the orebody is conducted to determine its shape, size, dip angle, and mineral composition. Based on this information, mining design is carried out.
Drilling pattern design: Based on the shape of the orebody and the thickness of the ore layer, a reasonable shallow-hole drilling layout is designed. The depth of the shallow holes typically ranges from several meters to dozens of meters, and the hole spacing and row spacing are determined according to the stability of the orebody and the extraction method. When designing the shallow-hole layout, the degree of ore liberation and blasting efficiency must also be considered.
2. Drilling and Blasting
Drilling operation: Shallow holes are drilled into the orebody according to the drill pattern design. Drilling machines typically use handheld or lightweight equipment, offering high maneuverability and suitability for working in narrow underground mine drifts. The drill hole diameter usually ranges from 50 mm to 100 mm.
Charging and blasting: Explosives are loaded into the drill holes based on the orebody characteristics and hole design for blasting. The shallow hole blasting technique effectively controls ore fragmentation and detachment, minimizing excessive damage to the orebody structure. The broken ore after each blast is recovered by gravity or mechanical means.
3. Ore Extraction
Staged Extraction: Ore extraction is typically conducted in multiple stages. After each blasting round, workers recover the broken ore, usually loading it into trucks or onto conveyor systems using mechanical or manual loading equipment for transport out of the mine.
Pillar Preservation: During extraction, portions of the ore are left intact as pillars to support the overlying ore body and surrounding rock, preventing mine collapse. These pillars are temporarily preserved and are extracted in the final phase. The arrangement and timing of pillar extraction are critical to stope stability. Pillar Recovery
Pillar recovery: After the upper portion of the ore body has been substantially extracted, the pillar recovery process begins. At this stage, smaller blasting charges may be used to detach and collapse the pillars, ensuring the stability of the underground structure.
Support and Reinforcement: After pillar recovery, the mine structure may become unstable, necessitating reinforcement. Common support methods include rock bolting and shotcreting.
5. Ore Transportation and Haulage
Transport System: In shrinkage stoping, ore transportation typically involves small-scale mechanical equipment (such as load-haul-dump machines or belt conveyors) to move the ore to the shaft hoisting station. Depending on the mine's geological conditions and design, the ore can be transported to the surface via mine cars, belt conveyors, or inclined shaft hoisting systems.
Surface Processing: Once hoisted to the surface, the ore is directed to the mineral processing plant for crushing, grinding, and mineral separation.
Process Description
Iron ore is the primary raw material for steel production, and steel is one of the core materials for modern industry and infrastructure. China is the world's largest steel producer and has enormous demand for iron ore. However, China's iron ore resources are characterized by low grade and high impurity content, requiring most iron ore to undergo beneficiation before use. Magnetic separation is the main beneficiation technology for iron ore in China, especially suitable for magnetite and vanadium-titanium magnetite. For non-magnetic or weakly magnetic ores such as hematite, limonite, and siderite, a combination of processes including roasting, gravity separation, high-intensity magnetic separation, and flotation is typically required to improve the yield and grade of iron concentrate.
Time period
2022
2026
Geography
China,Hebei
Geography comment
Forming Hebei's average data through merging data from multiple sources
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
Shallow-hole shrinkage stoping is a mining method commonly used for underground iron ore mining, particularly suitable for orebodies with small thickness and steep dip angles. The main characteristics of this method include staged shallow-hole blasting and ore extraction, combined with support from ore pillars and surrounding rock, to reduce subsidence and surface impact.