Legal Reforms as a Tool for Sustainable Development in Former Mining Communities: A Case Study of Kabwe Lead-Zinc Mine, Zambia

No Abstract

Pillar recovery using new wireless blasting technology: a case study in Vazante mine, Brazil

The application of explosives has never been considered as a major influencing factor during either the designing of a mine or the selection of the mining method. However, this has changed with the launch of WebGenTM wireless blasting system, which allowed underground mines to exploit their orebody applying methods previously not possible due to limitations imposed by the use of wired detonators. The wireless blasting system is based on magnetic induction communication, and its signal is capable of overcoming hundreds of meters through rock, water, and air, to reach individual primers in the blastholes without any physical connection.A noble application of wireless detonators is being used in Vazante mine, Brazil, an underground zinc mine where ore pillars are left in the mined stope to secure stability and minimize dilution by limiting the hydraulic radius. The recovery of these pillars is financially desirable but involves extra time and costs associated with scaling, backfilling, reinstalling infrastructure, accessing areas previously blasted (less stable), drilling, charging with explosives, and subsequently, firing and mucking out the blasted material with expected high dilution. Applying 100% wireless detonators made it possible to safely preload the pillar together with production blasts before losing access to the area, a method named Temporary Rib Pillar (TRP). After all the stope is mined and the pillar accomplished its objectives, the primers are initiated without neither the need for the extra cycles described previously, nor the need to re-enter the area. Thus, it was possible to reduce the exposure of people and equipment, reduce operational cycles, and increase ore recovery, directly contributing to anticipate the ore production while guaranteeing the safety of the teams involved.

HAULAGE ANALYSIS IN THE AIM OF THE COMBINED SYSTEM APPLICATION ON THE LEAD AND ZINC MINE "SASE" SREBRENICA

One of the most important influencing factors on the economy of mines with surface and underground exploitation is the correct choice of haulage technology of ore and waste. The paper analyzes the haulage of ore and waste in the Lead and Zinc Mine "Sase" Srebrenica and determines the optimal haulage length on the four excavation blocks for the application of the new haulage system by using the mine trucks from the aspect of set criteria, increasing capacity and reducing haulage costs through the techno - economic analysis and optimization.The optimal haulage length is determined through the calculations of the loader capacity and the possible choice of the truck depending on the stated criteria.

Occurrence, Distribution and Risk Assessment of Heavy Metals in Agricultural Soil and Water Around a Lead-zinc Mine in Southwest China

Mining activities could induce severe heavy metal pollution in soil and surface water, which would consequently pose potential ecological environment risks and human health risks. In this research, total 82 agricultural soil samples and 34 water samples were collected from a special area that surrounding a lead-zinc mine. Pollution level, source apportionment, ecological and health risks of heavy metals were evaluated based on the concentrations of cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). According to the results, Cd and Zn were obviously enriched metals in agricultural soil in the study area, meanwhile, the potential risks which calculated by geo-accumulation index were showed a high ecological risk due to high concentration of Cd found in local agricultural soil. Additionally, heavy metal sources analyzed by the PMF model could be classified into four categories: mining activity (Mn), parent material (Cr, Ni), atmospheric deposition caused by industrial and mining activities (Pb, Zn, Cd) and agricultural activities (Cu). Compared with the values specified by corresponding water quality standard, the heavy metals content in surface water were below these values except Cd, while the content of seven heavy metals in drinking water was within the safe limits. The bioavailability of Cd, Pb and Zn in soil were higher than other metals, and when the bioavailability of metals was consideration into health risk assessment, the total HI and TCR values were far below the accepted risk levels. Though human health risks were within the safe margin, the toxic hazards of heavy metals to residents and ecological should be taken into consideration.

Limnological Characteristics Reveal Metal Pollution Legacy in Lakes near Canada’s Northernmost Mine, Little Cornwallis Island, Nunavut

We compared modern limnological characteristics of three lakes near the world’s northernmost base metal (lead-zinc) mine, Polaris Mine, which operated from 1981 to 2002 on Little Cornwallis Island (Nunavut, Canada), to a suite of sites from Resolute Bay (Qausuittuq), Cornwallis Island. Although both study regions are underlain by broadly similar geology and experience nearly identical climatic conditions, present-day water chemistry variables differed markedly between sites on the two islands. Specifically, the lakes near the Polaris Mine recorded substantially higher concentrations of zinc and lead, as well as several other heavy metals (cadmium, molybdenum, nickel, uranium, vanadium), relative to the sites on Cornwallis Island. Although the Polaris Mine closed in 2002, elevated levels of heavy metals in our 2017 survey are likely a legacy of contamination from prior operations.