Environmental Impact of Electricity Consumption in Crushing and Grinding Processes of Traditional and Urban Gold Mining by Using Life Cycle Assessment (LCA)

Abstract

Abstract:Mining is not only an essential component of social and economic development since prehistoric time, but it also gives a large impact on our civilization. Gold is a noble metal that is highly valued. The extraction of minerals from earth is known as traditional mining. Gold also can be extracted from electronic waste or e-waste, and this new concept is called urban mining. There are many stages in traditional and urban mining process. However, in this study, the focus was on crushing and grinding processes to produce 1 kg of gold. Crushing and grinding are processes in the milling stage. This research evaluates and compares the environmental impacts of crushing and grinding processes, based on electricity consumption. About 50 to 65% of total electricity in milling was used for crushing and grinding processes. Life Cycle Assessment (LCA) methodology was used as a tool to evaluate the environmental burdens of electricity usage in converting ore and electronic waste to gold bars. The Life Cycle Impact Assessment (LCIA) of this process was interpreted by using Eco-indicator 99 assessment methods in SimaPro software. The impact categories included in this study were carcinogens, respiratory organics, respiratory inorganics, radiation, climate change, ozone layer, ecotoxicity, acidification or eutrophication, land use and minerals. The results showed that crushing and grinding from traditional mining gave the largest impact to the environment with single score of 399 Pt compared to the urban mining with only 1.81 Pt score. The highest impact in both types of mining is to human health.

Greenhouse Gases and Energy Intensity of Granite Rock Mining Operations in Thailand: A Case of Industrial Rock-Construction

“…gold), because of different mining methods, the results of the current analysis are inconsistent with some previous studies. In a sense, [7], [29], [30] reported that the utilization of electricity for mineral processing and mining operation was the largest contributor to total carbon emissions. Of this total, more than 50 to 80 percent of total electricity was used for crushing and grinding processes of gold mining [29]- [31].…”

Feasibility of Applying Clean Development Mechanism and GHGs Emission Reductions in the Gold Mining Industry: A Case of Thailand

“…This result is consistent with previous studies [22]- [24] that the combustion of fossil fuels to generate electricity is the largest source of CO2 emissions. Of these, more than 50 % of total electricity was used for crushing and grinding processes [25]. In comparison with other mines, [18] found that GHG emissions from lignite and limestone mining in Thailand were approximately 571,539 and 20,878 tCO2e per annual production capacity, respectively.…”

E-LCA of Two Microwave Absorbers Obtained from Slag of Copper Primary Production

“…Among these, the life cycle assessment (LCA) methodology [31] is used to assess the environmental benefits obtained choosing innovative materials containing slag instead of similar conventional products. The majority of these LCA analyses are related to the use of different types of industrial by-products [32][33][34][35][36][37] with the exception of other authors who have evaluated the environmental burden of copper slag [38][39][40][41][42][43][44]. As Kua [42,43], who has investigated copper slag recycling for cement and natural sand replacement and, De Schepper et al [44] who has assessed the environmental burdens of a concrete using different secondary products among these the CS as substitute of natural sand.…”