ANALIZA OZLJEDA U IRANSKIM RUDNICIMA

Mining is a high-risk industry that exposes operators and workers to a high level of occupational health and safety hazards caused by vehicle accidents, blasting, or collapse. This paper aims to analyse the serious and fatal accidents in Iran’s mines over a six-year period, from 2012 to 2017. The data sources were the statistical results of the occupational accidents reported by the National Statistical Centre of Iran and the importance measure of incidents defined by the questionnaires received from the mine safety and health experts. This research presents a model for the prioritization of the mining workplace based on the weighted injury risk of the occupational incidents in the mining industry. The results of this work show that the coal mines of Iran have the highest work-related incidence rate which requires special safety attention. Moreover, the total temporary disability risk is currently at the lowest level in all mining activities, while the fatality risk has significantly increased in the coal mines in recent years. The results obtained from this study are helpful to detect the dangerous mining workplaces and to protect workers from workplace hazards by considering the safety guidelines.Rudarstvo i rudarenje visokorizične su aktivnosti koje izlažu radnike i tvrtke velikim opasnostima unutar medicine rada i sigurnosnih rizika. One su uzrokovane nesrećama pri transportu, miniranju ili urušavanju. Ovdje su analizirane ozbiljne ili smrtonosne nesreće u iranskim rudnicima tijekom šestogodišnjega razdoblja, od 2012. do 2017. Izvori su bili statističke analize ozljeda u izvješćima Iranskoga nacionalnoga statističkog centra te podatci prikupljeni tematskim upitnicima od eksperata zaposlenih na rudničkoj sigurnosti i zdravlju. Prikazan je model određivanja prioriteta u rudarenju utemeljen na procjeni opasnosti od ozljeda na radu. Rezultati su pokazali kako iranski rudnici ugljena imaju najveću stopu nesreća te se stoga tamo trebaju razmotriti posebne mjere sigurnosti. Nadalje, najmanji su udjel imale ozljede koje su prouzročile privremenu radnu nesposobnost, dok su one sa smrtonosnim ishodom bile zadnjih godina najzastupljenije. Rezultati će pomoći kod opažanja opasnih radnih uvjeta tijekom rudarenja i tako zaštititi radnike od rizika upućivanjem na sigurnosne mjere

ODABIR NAJPRIKLADNIJE METODE EKSPLOATACIJE U IRANSKOME RUDNIKU ZLATA KODAKAN

The selection of mining methods is a challenging and complicated concept in mining engineering. It depends on various and different factors such as geotechnical, geological and economic properties and characteristics. Kodakan Gold Mine in Iran is currently mined using the open pit method. However, due to the special conditions of this mine and the increase in waste removal costs, it is inevitable to decide to select an underground mining method in the future. The purpose of this research is to select the most proper underground mining method for this mine. The shape, dip, and depth of the deposit, the thickness of the ore, grade distribution, recovery, skilled manpower, output per worker, and strength specifications of the ore, hanging-wall, and footwall are considered as the main decision attributes. Since there are different parameters in selecting the appropriate mining method using the multi-attribute decision making approach, therefore hybrid multi-attribute decision-making method was employed in this paper to enhance the strength of the decision model and eliminate the weaknesses of the classical methods. Regarding the results of this study, rock quality designation of the hanging-wall and deposit shape have the highest weight value in selecting the underground mining method. Moreover, the shrinkage mining method is proposed as the most appropriate method.Odabir eksploatacijske metode izazovan je i složen proces u rudarskome inženjerstvu. Ovisi o raznim čimbenicima kao što su geotehnička, geološka i ekonomska svojstva i karakteristike. U iranskome rudniku zlata Kodakan trenutačno se eksploatira površinskim kopom. Međutim, zbog posebnih uvjeta i povećanja troškova uklanjanja otkrivke neizbježno je u budućnosti odabrati određenu metodu podzemne eksploatacije. Cilj je istraživanja odabir najprikladnije metode podzemne eksploatacije za ovaj rudnik. Oblik, nagib i dubina ležišta, debljina rude, distribucija kvalitete rude, iskorištenje, kvalificirana radna snaga, učinak po radniku, čvrstoća rude, krovine i podine smatraju se glavnim parametrima za odluku. Zbog različitih čimbenika u odabiru odgovarajuće metode eksploatacije pri pristupu odlučivanja s više parametara korištena je hibridna metoda odlučivanja kako bi se povećala uspješnost modela odlučivanja i otklonili nedostatci klasičnih metoda. Rezultati istraživanja pokazali su da najveću težinsku vrijednost pri odabiru metode podzemne eksploatacije imaju indeks kvalitete jezgre krovine i oblik ležišta. Pored toga, natkopna metoda predložena je kao najprikladnija metoda podzemne eksploatacije

The Dangerous Condition of Ground during High Overburden Tunneling (A Case Study in Iran)

Knowledge of the ground condition and its hazards can play an important role in the selection of support and suitable excavation method in underground structures. Water transport tunnel is one of the most important structures with regard to the goal of excavation, special conditions and limitations considered in the design and execution of them. Beheshtabad Water Conveyance Tunnel with 64930 meters length, 6 meters final diameter is the largest water Conveyance tunnel in Iran. Because of high over burden and weak rock in the most of tunnel path, the probable hazardous of the ground condition such as squeezing and rock burst must be studied. Squeezing stands for large timedependent convergence during tunnel excavation. This phenomenon occurs in weak rocks and deep conditions. Besides, the height of overburden in some of the zone tunnel is about 1200 meters. The occurrence of this phenomenon is always together with the instantaneous release of strain energy stored in the rock materials, causing the harm to the personal equipment and the collapse of underground structures. The existence of high thickness overburden in some the zones of this project indicates the high potential of rock burst hazard. In this research, the length of the tunnel has been partitioned into sections using the interpreted geological, geophysical studies and borehole data. After evaluating rock burst and squeezing potential with alternative analytical and experimental methods for each section, the results of dierent methods were compared with each other. Results predict low to moderate squeezing potential and moderate to high rock burst potential for some panels of the tunnel

ODABIR NAJPRIKLADNIJEGA NAČINA BUŠENJA I MINIRANJA UPOTREBOM MADM METODA (STUDIJA SLUČAJA: RUDNIK ŽELJEZA SANGAN, IRAN)

Drilling is the first stage of open pit mining that has a considerable effect on the other stages of mining, including blasting, loading, hauling and crushing. An unsuitable drilling pattern may lead to undesirable results such as poor fragmentation, back break and fly rock that not only results in technical and safety issues but also increases the operating cost of the mine. Multi-Attribute Decision-Making (MADM) methods can be useful approaches to select the appropriate drilling pattern among various alternatives, performed previously. This paper aims to select the most proper drilling and blasting pattern for Sangan Iron Mine, Iran. To achieve this, in the first step, rock fragmentation, back break, fly rock, specific charge and specific drilling were considered as the decision criteria and their degree of importance was calculated using the AHP method under a fuzzy environment. Then, TOPSIS and PROMETHEE methods were used to select the most proper alternative. The results of this study show that the drilling pattern with a spacing of 5 m, burden 4 m, hole depth 10 m, and hole diameter 15 cm is the most suitable one. The stemming length and powder factor of the suggested pattern are 2.3 m and 2.6 gr/cm3, respectively.Bušenje je prva faza površinske eksploatacije koja ima znatan utjecaj na ostale faze rudarenja, uključujući miniranje, utovar, transport i drobljenje. Neprimjeren način bušenja može dovesti do nepoželjnih rezultata poput loše fragmentacije, povratnoga loma i odbacivanja stijena, što ne samo da rezultira tehničkim i sigurnosnim problemima, već i povećava operativne troškove rudnika. Metode donošenja odluka s više atributa (MADM) mogu biti korisne za odabir odgovarajućega načina bušenja među raznim prethodno izvedenim alternativama. Cilj je ovoga rada odabrati najpogodniji način bušenja i miniranja za rudnik željeza Sangan, Iran. Da bi se to postiglo, u prvome koraku kao kriteriji za odlučivanje razmatrani su fragmentacija stijena, povratno lomljenje, odbacivanje stijena, specifično punjenje i specifično bušenje, a njihova važnost izračunana je korištenjem AHP metode u neizrazitome okruženju. Zatim su korištene metode TOPSIS i PROMETHEE za odabir najprikladnije alternative. Rezultati ove studije pokazuju da je najprikladniji način bušenja s razmakom od 5 m, opterećenjem od 4 m, dubinom rupe od 10 m i promjerom rupe od 15 cm. Duljina čepa bušotine i specifična potrošnja eksploziva predloženoga uzorka iznose 2,3 m, odnosno 2,6 g/cm3

Artificial neural network to predict the health risk caused by whole body vibration of mining trucks

Drivers of mining trucks are exposed to whole-body vibrations (WBV) and shocks during the various working cycles. These exposures have an adversely influence on the health, comfort and also working efficiency of drivers. Determination and prediction of the vibrational health risk of the mining haul trucks at thevarious operational conditions is the main goal of this study. To this aim, three haul roads with low, medium and poor qualities are considered based on the ISO 8608 standard. Accordingly, the vibration of a mining truck in different speeds, weights and distribution qualities of the materials in the dump body are evaluated for each haul road quality using the Trucksim software. An artificial neural network (ANN) is used to predict the vibrational health risk. The obtained results indicate that the haul road qualities, the truck speeds and the accumulation sides of material in the truck dump body have significant effects on the root mean square (RMS) of vertical vibrations. However, there is no significant relation between the material’s weight and the RMS values. Also, the application of ANN revealed that there is a good correlation between the predicted and simulated RMS values. The performance of the proposed neural network to predict the moderate and high health risk are 88.11% and 93.93% respectively</span

Application of analytical hierarchy process to selection of primary crusher

Selection of crusher required a great deal of design based on the mining plan and operation input. Selection of the best primary crusher from all of available primary crushers is a Multi-Criterion Decision Making (MCDM) problem. In this paper, the Analytical Hierarchy Process (AHP) method was used to selection of the best primary crusher for Golegohar Iron Mine in Iran. For this reason, gyratory, double toggle jaw, single toggle jaw, high speed roll crusher, low speed sizer, impactor, hammer mill and feeder breaker crushers were considered as alternatives and capacity, feed size, product size, rock compressive strength, abrasion index and mobility of crusher were considered as criteria. As a result of our study, the gyratory crusher was offered as the best primary crusher for the studied mine. Keywords: MCDM, Analytical Hierarchy Process, Primary crusher selection, Golegohar Iron Min

Reliability analysis of the compressed air supplying system in underground mines

Despite the high cost and low efficiency, compressed air is mostly used in underground mining for ore extraction, hoisting, and mineral processing operations. Failures of compressed air systems not only threaten the health and safety of workers but also contribute to inefficient control of airflow and stopped all equipment that operates by compressed air. In such uncertain conditions, mine managers are faced with the big challenge to supply enough compressed air, and therefore, the reliability evaluation of these systems is essential. This paper aims to analyze the reliability of the compressed air system using the Markov modeling approach as a case study, Qaleh-Zari Copper Mine, Iran. To achieve this, the state space diagram was constructed considering all relevant states for all compressors in the main compressor house of the mine. The failure and repair rate of all main and reserve compressors were calculated for all possible transitions between states to obtain the probability of being of the system in each of the states. Moreover, the probability of failure at any time period was considered to study the reliability behavior. The results of this study show that there is 31.5% probability that the compressed air supplying system is in operating condition with two main and one standby compressors. The system probability that two main compressors are remain in the operation without failure for one months is 92.32%. Furthermore, the lifetime of the system is estimated 33 months when at least one main compressor is active.Validerad;2023;Nivå 2;2023-05-10 (hanlid)</p

The reliability and maintainability analysis of pneumatic system of rotary drilling machines

In any blasthole drilling the bottom of theblasthole must be kept clean by evacuating drill cuttings orit flushing as soon as they appear to ensure efficient drilling.If it is not done well, a large quantity of energy will beconsumed in regrinding with the consequent wear on drillbit and decrease penetration, apart from the risk of jamming.Therefore, research on reliability and probability ofsafe operation of pneumatic system of drilling machines isof prime importance to ensure safe drilling operations. Inthis paper, reliability of this system was modeled andanalyzed. To doing this research, drilling machines inSarcheshmeh Copper Mine in Iran have been selected fordata collection and analysis. After reliability modeling ofpneumatic system, maintenance scheduling has been presentedbased on different reliability levels. There were fourrotary drilling machines in this mine (named A, B, C andD). Results showed that after about 7 h drilling ofmachines A and B, and after 103 and 44 h drilling ofmachines C and D respectively, noticeably the reliability ofpneumatic system reached to 80 %. As a result, machinesC and D have more reliable pneumatic systems in comparisonto machines A and B and checking and servicing ofpneumatic system before these time was essential. Also,maintainability analysis showed that more failures ofpneumatic system of machines A, B, C and D will benoticeably repaired at about 28, 34, 6 and 9 h.Godkänd; 2013; 20131213 (hadhos