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By M. Louarrat, G. Enaime, A. Yaacoubi, A. Baçaoui, J. Blin

"The purpose of this study is to prepare a new activated carbon from olive stones for use in gold recovery by carbon-in-leach (CIL) and carbon-inpulp (CIP). The preparation method chosen was physical activation using steam. The effect of four process parameters: the residence time for carbonization, the activation temperature, the residence time for activation, and steam flow, were studied by the mean of response surface method (RSM) in order to optimize the yield, iodine index, and attrition characteristics. These two last responses were used as primary indicators of gold recovery capacity and mechanical strength. The results obtained show that optimal activated carbon can be prepared under the following conditions: a carbonization time of 157 minutes, activation at 921°C for 53 minutes, and a water vapour flow of 0.18 mL/min. This optimum carbon has an iodine value greater than 1100 mg/g and an attrition index in the order of 0.74%. These values reflect the quality of the precursor (olive stones) as a raw material for the development of an effective new activated carbon for the gold mining industry. IntroductionActivated carbon is an effective adsorbent widely used in industry due to its high surface area, well-developed reproducible microporous structure, and high degree of surface reactivity and adsorption capacity. World consumption of activated carbon is steadily increasing. It is primarily used in industrial wastewater and gas treatment and also for silver and gold recovery from cyanide solutions (Syna and Valix, 2003; Soleimani and Kaghazchi, 2008; Buah and Williams, 2010; Eddy et al., 2011). However, activated carbon is expensive and it needs to be regenerated after each adsorption cycle. In order to decrease the cost of manufacturing activated carbon, low-cost forest and agricultural wastes are considered promising new materials. In recent years considerable research has been reported on activated carbon from agricultural wastes, such as olive stones (Yavu et al., 2010), acorn shells (Sahin and Saka, 2013), peanut shells (Wu, Guo, and Fu, 2013), grape seeds (Jimenez-Cordero, 2014), coconut shells (Yalcin and Arol, 2002; Gratuito, 2008), palm shells (Sumathi, 2009), cherry stones (Jaramilloa, Gomez-Serrano, and A´lvareza, 2009), macadamia nut shells (Eddy, 2011), apricot stones (Soleimani and Kaghazchi, 2008), and bagass (Syna and Valix, 2003)."

Mar 1, 2019

By C. A. Rawlins, P. Rostami

"Ventilation systems are not only an integral part of any underground mine design but are a significant contributor to the mine’s capital and operating costs. The ventilation and cooling design systems presented in this paper were part of the prefeasibility evaluation of an underground platinum mine in South Africa. The mine would ultimately operate at the depth of 1,200 m below surface with a proposed 4 Mtpa production rate. The proposed mining operation is a highly mechanized operation using diesel equipment. Significant daily production rate, large amount of equipment and expansive nature of the operation, contributed to a challenging while flexible ventilation design requirements. This paper presents how to safely and efficiently optimize capital expenditure and operating costs associated with the mine air cooling and refrigeration system through practical ventilation design practices. Successful capital and operational savings by modulating installation and commissioning of refrigeration facilities can influence the economic realization of such systems. The adapted planning and design approach provided a cost-effective advantage while complying with design safety and regulations. INTRODUCTION This paper outlines a prefeasibility evaluation of the heat loads and related cooling system to be employed at the proposed platinum mine. The paper also provides appropriate details for a comprehensive understanding of the applied methodology. The proposed mine will be a trackless underground operation using a combination of mining methods. Initially, ore zones with vertical thicknesses greater than or equal to 18 m will be mined using the long-hole stoping (LHS) method, while thinner ore zones will be mined using mechanized drift-and-fill or drift-and-bench methods; hence, a highly mechanized operation with LHDs, trucks, drill rigs, personnel carriers, etc. is envisioned. Broken rock (ore and waste) will be transported by the means of trucks to the main passes (ore and waste) and collection points. Mining zones identified in the project occur at depths ranging between approximately 700 m to 1,600 m below surface. Primary access to the mine will be via a 1,100 m deep, 10 m diameter production shaft (named Shaft No. 2), three additional shafts will be sunk to provide future ventilation and production support. Three main access levels are established as primary haulage levels and include a series of interconnecting ramps. Additional mining sublevels will be developed as necessary. Figure 1 shows the proposed shaft locations and main access levels in a 3-D elevated view. Mining is performed using highly productive mechanized methods. For this reason, an annual ventilation estimate is based on requirements for mobile equipment (i.e., 0.06 m3/s/kW). The air requirements imposed on the underground operation is further influenced by equipment heat loads, auto compression, and virgin rock temperature, as the main sources of in-mine heat."

Jan 1, 2015

By D. R. Kalasky, J. M. Mutmansky, B. Kolonja

This paper considers simulation of truck dispatching systems using maximum expected production of the truck-shovel system as the measure of performance. Two analysis methods are utilized: multiple comparisons with the best (MCB) and the combination of MCB with the variance reduction technique known as common random numbers (CRN). These two techniques are compared via simulation experiments. Results show that the combined procedure of MCB with CRN is the superior tool to use to reduce the total number of replications needed to ensure the specified probability of correct selection from a number of systems. In this case study, MCB with CRN reduced the variance by 29% and the number of required replications by 48%. Also, the MCB with CRN procedure narrowed the confidence interval by 18%.

Jan 1, 1995

By B. Kolonja

This paper considers simulation of truck dispatching system designs using maximum expected production of the truck-shovel system as the measure of performance. Two methods are utilized, multiple comparisons with the best (MCB) and the combination of MCB and the variance reduction technique known as common random numbers (CRN). These two techniques are compared via simulation experiments. The results show that the combined procedure of MCB with CRN is the superior tool to reduce the total number of replications needed to ensure the specified probability of correct selection over the finite number of designing systems. In this case study, MCB with CRN reduces the variance by 29% and the number of required replications by 48%. Also, the MCB with CRN procedure narrowed the confidence interval by 18%.

Jan 1, 1994

By Ahmad Amini, Hadi Abdollahi, Pouya Karimi

Due to detrimental effects of cyanidation process on the environment in gold industry, application of cyanide alternatives such as thiourea are being highly considered in recent projects. In this study, the extraction of gold from poly metal ore, using thiourea was precisely investigated. The representative sample contained 2.5 ppm Au and 160 ppm Ag. The sample was categorized as oxide gold ore, because the main part of its pyrite was changed to iron oxide and hydroxide such as goethite and lepidocrosite. According to mineralogy, the main gangue mineral was quartz. It shows that gold grains are free and interlocked with quartz matrix. Also, the presence of a high amount of silver in free and sulfide forms and also the low content of other sulfide minerals such as base metal sulfides is a remarkable point of these studies. In the gold extraction process with thiourea, there are several parameters that affect the rate of gold dissolution such as concentrations of thiourea as a gold lixiviant and ferric sulfate as an oxidant, pH and size fraction of feed and leaching time. The influence of these parameters on the gold dissolution rate were investigated and optimized. The results showed that the concentration of thiourea is the most influential parameter which could increase the gold recovery to 71% (at 10 g/kg sample). The optimal amount of ferric sulfate was determined as 6 g/kg sample. Also, the optimal levels of size fraction of feed and pH of solution were 88% under 75 micron and 2 as acidity; respectively. Leaching time was 6 hrs. In addition, this sample was leached with cyanide and the optimized values of size fraction of d88=75 microns, pH=10.45, 2500 ppm of sodium cyanide with time leaching of 24 hours were concluded for maximum recovery of gold in solution. Finally, the results of cyanidation tests were compared to the thiourea dissolution after optimizing all affected parameters in cyanidation process.

Jan 1, 2018

By Ataç Başçetin, Hasan Çelt, Hüseyin Onur Dönmez, Kürşat Hasözdemir

Phenolic foams, known for fire resistance, show broader industrial potential, particularly in mining, through property enhancements. Adjustments to the formaldehyde-to-phenol (F/P) ratio, bio-based additives like lignin, and nano-silica improve foam strength and thermal stability. Density modifications allow foams to range from flexible, low-density forms to rigid, high-density supports. In mining, enhanced phenolic foams could reduce coal ignition risks by acting as oxygen-blocking barriers. Current findings suggest these foams offer viable, sustainable solutions for safety in hazardous environments. Continued development could make them essential for thermal and mechanical applications under extreme conditions. This paper aims to provide a comprehensive overview of the mechanical characteristics of phenolic foams, current enhancement strategies, and standardized testing methods used to evaluate foam properties.

Feb 1, 2025

By R. D. Alorro, B. Tadesse, E. Aghaei

Cinnabar (HgS) and native mercury (Hg) are the most common naturally occurring forms of mercury found in most gold ores subsequently released into the environment during processing. Mercury and its compounds are extremely toxic and recognised as serious health and environmental hazards. This research investigates the possibility of mercury (Hg) removal from waste solutions from gold processing using iron-aluminium (Fe-Al) bimetallic particles. The synthesis of Fe-Al bimetallic particles using zero-valent aluminium and ferric chloride as precursors were performed following the optimisation of influencing factors. The presence of both metals in the prepared bimetals was confirmed by XRD analysis. The experiments for mercury removal by bimetals were designed using the central composite design and Minitab software based on two variables including contact time and adsorbent dosage. The best result of Hg(II) removal (>90%) was achieved using 4 g/L bimetals and contact time of 75 min. However, the statistical analysis of results indicated that these parameters have only a minor contribution to the removal of Hg(II) by Fe-Al bimetals. Higher bimetal dosage and contact time resulted in a higher Fe dissolution from the Al surface which can be attributed to the presence of nitrate (# $) ions in the solution. However, adding 0.1 M NaCl to the Hg solution had a positive impact on Hg removal by improving the conductivity and electron transfer within the solution. The Fe-Al bimetallic particles are promising substances for further testing of Hg removal from gold processing waste solutions with different conditions and constituents. Keywords: Mercury removal, gold processing, Fe-Al bimetals, optimisation

Jan 1, 2020

By Liming Yuan, Wei Tang, RICHARD THOMAS, DAVOOD BAHRAMI

The location and orientation of fire suppression nozzles is critical in suppressing mobile mine equipment fires. To effectively suppress such fires, optimization needs to be considered for the suppression nozzle locations and discharge angle. Detailed experiments were conducted to study the effectiveness of fire suppression agents with different nozzle configurations. A variety of fire suppression systems including dry chemical, wet chemical, dual agent (dry and wet chemical), carbon dioxide, and water mist were used. Six types of nozzle locations were studied, and their fire suppression effectiveness were compared. Results from this work highlight potential considerations when determining effective fire suppression designs.

Feb 1, 2025

By Bengt T. Andersson

Outokumpu Consulting Engineers, Outokumpu Oy SF-02200 Espoo 20, Finland This paper describes experiences from some operating non-ferrous flash -smelters and focuses on the advances in smelter byproduct and gas treatment engineering design. In this context a summary is given of the specific technical and economic benefits achieved-by flash -smelting technology and oxygen enrichment. The paper will also briefly outline a few new process and equipment developments.

Jan 1, 1983

By A. Noble

"Froth flotation circuits are widely used throughout the mineral processing industry for the concentration of fine particles. It had been estimated that nearly 2 Gt (2.2 billion st) of ores are treated globally each year using this versatile separation process (Fuerstenau, 1999). Due to the high feed tonnage, a large economic incentive exists for flotation plant operators to optimize the performance of this critical processing circuit. Prior to the 1950s, the optimization of flotation circuits primarily involved the manual adjustment of operating variables based on visual observation and sporadic sampling (Lynch, Harbort and Nelson, 2010). During the next several decades, however, the advent of improved on-line instrumentation coupled with the rapid development of high-speed microprocessors allowed the industry to develop more advanced control systems that could quickly adjust operational parameters in response to disturbances in ore characteristics and plant flows. These early online controls typically involved feedback loops designed to stabilize cell performance through the automatic manipulation of process variables such as pulp levels, gas rates and chemical dosages. The set-points for these controllers were often set by plant operators based on one or more operator objectives, such as maximizing throughput, recovery or grade. More recently, these regulatory controllers have been interfaced with high-level data display and management systems that provide operators with the ability to better optimize flotation plant performance based on mathematical models and rule-based algorithms (Greet, 2010).While tremendous strides have been made during the past several decades, even the most modern flotation plants are still faced with the long-standing question: “What are we trying to optimize?” From an operator perspective, some common responses include “Maximize tonnage of saleable concentrate” or “Maximize metals recovery at a customer-specified market grade.” These replies may or may not reflect those of management, who often focus on economic goals such as “Maximize profits for each operational unit” or “Maximize rate of return for all corporate assets.” Unfortunately, these high-level objective statements do not always translate well into practice due to the disconnect between plant operating protocols and product value. Attempts have been made by industry to overcome this issue using various types of optimization routines such as linear programming or other optimization engines. While this approach does have some merit, these blind routines require considerable input data and interpretational expertise and provide little or no fundamental insight that can be used to drive improvements in concentrator performance."

Feb 1, 2017

By Rajesh Sonkar, Sanjeev Kumar

The deployment of Dragline machines in opencast coal projects involves huge capital expenditure as well as operating costs. The mine operators always endeavor to ensure smooth excavation of material by the Dragline machines while meeting the major objectives of safety, minimal disturbance to environment and optimal operating costs. Optimization of fragmentation through well designed blasts is fundamental in meeting part of the objectives is good fragmentation of rock or mineral proposed to be lifted by the Dragline machine. If the overburden lying over mineral is not properly fragmented, it may result in formation of ‘Toe’ the removal of which is the most arduous task in opencast coal mines. The mine operators always endeavor to achieve best possible results in blasting to ensure smooth operation of the high cost Dragline Machine. However, despite continuous efforts by the blasting engineers involved in bench blasting for the machine, the formation of ‘Toe’ is an ever nagging problem faced in large opencast coal projects eventually reducing the overall operational efficiency of mining.

Jan 1, 2011

By Ashutosh Shandilya

Froth flotation is a selective separation process and rarely used for beneficiation of limestone in the world as compared to other minerals and also mostly known conventional methods of up gradation of ROM including wobbling, selective mining, sorting, preblending etc. Limestone is mainly used in the manufacture of cement, steel and chemical industries. High grade limestone deposits are depleting day by day and the requirement of the industries have to be met by beneficiating the low grade limestone deposits in the world. And because of marginal quality of limestone, it cannot be directly used in cement industry. At ACC Madukkarai cement works, Coimbatore, Tamilnadu, full fledged mineral beneficiation process is adopted to enhance the quality of low grade lime stone from 38-42 % CaO to 45-47 % CaO and silica reduced from 19-22 % to 11-13 % by use of oleic acid (commercial grade and vegetable origin) 0.38 kg/ton of limestone and caustic soda 0.05 kg/ton of limestone. Keywords: OK-8 Cells, Froth flotation process, Beneficiation studies, Low-grade lime stone, Oleic acid, % solids, Pulp density, Ph, Iodine value, saponification value, Denver cell

Sep 1, 2012

Conditional simulation provides a model of the ore body that represents variability in the data. This can be used to determine the impact of various grade control and mining strategies. A number of transfer functions are discussed that assist in optimizing grade control sampling. The cost effectiveness of various drilling and trenching techniques are discussed. Modelling of the expected performance of a mill head grade sampler is investigated. Conclusions are drawn about the likely impact of various sampling techniques on the economic performance of an operation and about applying sampling theory to grade control sampling.

Jan 1, 1999

By Detlef Ehlert

Flexibility in terms of producing high sophisticated products with an exceptional wide range of properties and dimensions requires physical based process models for the generation of optimal set points. Therefore SMS applies since many years an integrated PSC® (pass schedule model), PCFC® (profile, contour and flatness model) and CSC (cooling section control) for the use in hot strip mills, CSP® plants and plate mills offering best possible product tolerances. Focus during the development of the model was made on the best possible physical description of the rolling process to minimize the need of complex adaptation algorithms. As an addition SMS has also developed a microstructure model to ensure the quality control with respect to mechanical properties and to save up the needs of taking samples. Beside of this the modular design of the Microstructure and Material Property Model (MPM) offers additional benefits to improve the accuracy of the other models, e. g. the recrystallization model in the finishing mill. Using the results of that model strain hardening or softening effects during rolling can be predicted and an optimum pass schedule can be calculated to avoid rolling stability problems related to phase transformation.

Aug 16, 2017

By Kristin K. Mueller, Lucie Coudert, Thi Yen Chau Nguyen, Lan Huong Tran, Jean‑François Blais, Guy Mercier

Fluorite (calcium fluoride—CaF2), also known as fluorspar, is an industrial mineral used in metallurgy, hydrofluoric acid production, and ceramics manufacturing. Based on the results from a previous study, a low-grade fluorspar by-product (20.0% CaF2) originating from the exploitation of a rare earth carbonatite deposit can be improved to 75.4% by combining magnetic separation and acid leaching. The present research aimed to develop and optimize a column flotation process to increase the purity of this fluorspar by-product by removing residual silicate minerals and meeting the requirements for ceramic manufacturing (> 85% CaF2). The optimal flotation conditions required for maximizing the recovery and improving the grade of a fluorspar by-product were identified using a conventional approach combined with a response surface methodology (Box-Behnken design). Optimal fluorspar flotation was achieved under the following conditions: 3.6 g/kg of sodium oleate as the collector, 2 g/kg of sodium silicate as the pH modifier and depressant, a conditioning time of 35 min, a flotation time of 7 min, and a solid-to-liquid ratio (S/L) of the pulp of 5%. Under these conditions, 86.8% fluorspar recovery was achieved, and the grade increased from 76.5% in the feed (metallurgical grade) to 88.6% (ceramic grade) in the final concentrate. The silicon content decreased from 5.66% in the feed to 1.12% in the fluorspar concentrate. Using magnetic separation before the flotation improves the final content of fluorspar in the concentrate with the final grade of 94.4%.

Sep 9, 2022

By Hasan Sevim

This paper summarizes recent developments in modeling of underground coal slurry haulage networks for determination of optimum design and operating parameters. The model presented here is based on a stochastic dynamic programming formulation, applicable in any typical room-and-pillar and/or longwall mining configuration commonly practiced in the United States. The formulation and the structure of the model is general enough to handle design problems involving more than one face and mining method. Given the stochastic operating characteristics and a system layout, the model can be used to determine the equipment configuration and operating regimes that minimize the overall unit cost of coal haulage.

Jan 1, 1983

By Sah Rameshwar, T. Umadevi, K. S. SRIDHARA

In the magnetite iron ore pelletization process, oxidation of magnetite followed by sintering of the oxidized magnetite (hematite) is desirable. Optimum preheating time & temperature and roasting time & temperature is required to get the desired properties of the pellets with magnetite, hematite, and hematite–magnetite blend. In order to utilize the magnetite resources in a current induration furnace, which is designed for hematite resources, detailed pelletization studies have been carried out to optimize the firing cycle for magnetite concentrate as well as magnetite with hematite concentrate. Under optimum conditions, such as preheating temperature 1000–1150 °C, preheating time 10 min, roasting temperature 1250 °C and roasting time 7.5 min, the cold compression strength (CCS) of magnetite roasted pellets was 325 kg/p, and this was due to recrystallization of secondary hematite particles, and development of the strong slag bond between primary and secondary hematite particles. The strength of hematite concentrate pellets was 260 kg/p. From laboratory studies, it was found that without disturbing the induration furnace firing cycle, which is designed for hematite ore ~5%, magnetite concentrate can be used along with hematite concentrate in pellet blend and the strength of the pellets was 270 kg/p. As the magnetite concentrate increases in the blend beyond 5%, the preheating zone residence time should be increased or a supply of extra oxygen is required. Laboratory as well as plant investigation has shown that the addition of magnetite to the hematite mix blend improved the strength of the pellets compared to hematite pellet alone.

Oct 26, 2020

By Corby G. Anderson

"Laboratory testing using industrial electrowinning solutions was performed to determine the best Faradic cell efficiency for copper cathode recovery. The variables tested were solution flow rate, recycle ratio, reagent addition combinations of guar and thiourea, and addition amount of acid mist suppressant CAL FAX DBA-70. The ideal flow rate was determined to be 37.85 litre/min. Additionally, the ideal recycle ratio was determined to be 10:1. The reagent addition scheme from testing which showed the highest efficiency was with 680 g/tonne guar of cathode copper won and with 135 g/tonne thiourea of cathode copper won. These values for reagent addition only reflect the best efficiency and should not be assumed to be the best reagent concentration for copper purity. The amount of foaming agent that showed the best efficiency was the test with 2 ppm of foaming agent. Again this amount of reagent is based on efficiency and should not be taken as the amount of reagent that does the best acid mist suppression. Additional proprietary surface characterization work indicates these additives may have enhanced the cathodic reduction surface morphology of some noble minor impurities. Subsequently, these operating parameters were introduced into the plant operation and proved successful after their implementation.BACKGROUNDCopper electrowinning has become a dominant technology for the production of marketable high grade copper cathode products. The literature is robust with applications, optimizations, additives and developments in this field (e.g., Classens & Harris, 1990; Pfalzgraff, 1999; Tozawa, Su, & Umetsu, 2003; San Martin, Otero, & Cruz, 2005; Houlachi, Edwards, & Robinson, 2007; Romero, Avila, Fester, & Yacher, 2007; Marsden, 2008; Beukes & Badenhorst, 2009; Vainio & Weatherseed 2009; Bender, 2010; Joy, Staley, Moats, Perkins, Uhrie, & Robinson, 2010; Khouraibchia & Moats, 2010; Moats, 2010; Rutledge & Anderson, 2015).Tests of forty hours duration and at room temperature were performed for this project using samples of actual industrial electrowinning solutions. These industrial solutions were comprised of 60 g/L Cu plus 65 g/L Ni, 3 g/L Fe, and 30 g/L free sulfuric acid. Other confidential minor impurities were also present including some solubilized precious metals. The testing apparatus utilizing stainless steel anodes and cathodes is illustrated in Figures 1 and 2."

Jan 1, 2016

By K. Hori

In this study, the determination of optimal conditions for jig separation has been investigated with a TACUB jig separator. The TACUB jig, from which a Batac jig originated, is a useful gravity separator that is effective to separate crushed solid wastes as well as coarse ores. A mixture of crushed polyethylene (specific gravity 1.3) and polyvinyl chloride (specific gravity 1.5) was separated by a batch TACUB jig by varying the frequency (wavelength) and the amplitude (pulse stroke length). It was found that the sample particle layer in the separation chamber was fluidized without turbulence by the rising water pulse resulting in the separation. However, a too strong water pulse reduced the efficiency of the separation of the particles. The results indicate that the specific velocity of the rising water is necessary to fluidize the particle layer without turbulence to separate the particles. The expansion ratios of the thickness of the particle layer in rising flows were measured in a cylindrical column. The pressure losses by the particle layer were calculated from the expansion ratios and the velocity of the rising flows by Ergun?s equation. The curve of the pressure loss vs. the velocity of rising flow showed a maximum point corresponded to the point of fluidization. The velocity of a rising flow on the point of fluidization provided the optimal separation condition.

Jan 1, 2014

By P. Valicek

Anglo American Platinum Limited is constantly striving to improve safety and productivity. There are many different initiatives taking place within the organization in order to ensure continued safe operation and profitable ounces for the future. One of the opportunities and potential growth areas that has been identified and is being explored is that of mechanization. In order to do this, the approach that has been adopted by Anglo American Platinum is to fully understand and analyse the current mechanized mining methods. Once each configuration is fully understood, the method can then be optimized and new mining technologies and systems can be developed to overcome the current shortfalls. This paper will discuss a methodology that was developed by Anglo American Platinum (in conjunction with Cyest Corporation) and adopted to optimize the mechanized mining layout and fleet configuration, and will also present the final findings of the study. Due to the impracticability of piloting every possible option in the workplace, extensive modelling and simulation exercises were conducted to determine realistic parameters for productivity and value. The study resulted in a full understanding of mechanized mining systems and their associated layout. From the results of the study a mining / logistic layout was developed which highlighted the following opportunities: 1. Create safe operations through the reduction of personnel in the ?high-risk zone? of stopes 2. Separate machines and personnel by use of remotely operated machines 3. Create focused mining on primary development from the production stoping, thus having dedicated teams on development and stoping. 4. Develop primary development ahead of the stoping activity. This enables: a) Understanding of the geology and subsequent implementation of the correct b) technology (?fit-for-purpose?) required to mine that area based upon this geological knowledge c) Ability to install tipping points ahead of stoping, creating ?immediate stoping reserves?, thus increasing flexibility and reducing production risk d) Improved productivity by having adequate faces available and reduction in re-development to establish faces. 5. Quicker return on Investment due to recovering revenue from ?on-reef development? 6. The layout allows flexibility between stope sections enabling better ?resource sharing? 7. Optimize the long-term ratio of machine makeup of the fleet in relation to the production outputs 8. Creates an agile mining layout allowing rapid response to market pressures. The findings and work presented in this paper is currently being implemented at different test sites within Anglo American Platinum and will demonstrate that improved safety and productivity can be achieved through the adoption of mechanization.

Jan 1, 2012