ARM Pty Ltd: Providing Hard-Facing Products And Services To Mining Sector (Essay).

Case Studies and Cost-Benefit Analyses of Hard-Facing Applications

Following the previous research carried out by Abrasion Resistant Materials Pty Ltd found online at https://www.arm.com.au indicates that Abrasion Resistant Materials (ARM) Pty ltd is a Brisbane based entity with the aim of providing hard-facing products or services to mining based sector. Following the company’s web-site, information based on particular hard-facing applications that have attempted with loaders as well as excavators, dragline-buckets, dozer along with edges being inclusive are contained. Costing analysis that is very much instrumental in the determination of the process viability and has also been carried out by Abrasion Resistant Materials (ARM). The information available in the company’s website provides various techniques of hard-facing mining applications with several case studies as well as cost-benefits analysis.

Kenneth Budinski who is a metallurgical consultant analyzed various facets of surface engineering hence compiled a book that was useful in the initial examination of various types of wear as well as describing the measures that can employed to help in the reduction of this wear. Following his previous research as indicated in his book, an invaluable asset was proven that was very essential in the identification of various types of wear being analyzed as well as suggesting other techniques this was effective in the minimization of wear. Further examination indicated that various types of coatings could be employed on a material when applying technique of hard-facing with the aim of increasing its wear resistance. Moreover, consumables which are applicable in hard-facing techniques were further identified with their environmental impacts as well as surface engineering history being examined. A part from the topic indicated above, the book only provides little amount of additional information needed with the remaining details showing processes of various techniques of hard-facing that seem to be beyond the scope of the project report.

Another suitable and relevant study found online was cladded-water plates find-mining applications is at https://www.cladtechnologies.com/Articles/Minetec/mintec.htm which details information on the hard-faced use, cladded-water plates found on dragline-buckets that is capable of counteracting the water effects. It details hard-facing use day to day life as well as its historical background. Equally, comparative analysis of Hardness against Wear is well elaborated that is very useful in the establishment of particular type of hard-facing required for wear counteraction. A good chunk of information presented on hard-facing is based on hard-facing the original item, instead of placing a hard-faced plate over the water area. Whist it is difficult to use cladded-water plates in each and every applications, its analysis will be essential in evaluating other different or extension of hard-facing.  A detailed analysis of the website fails to present any evidence of the actual benefits associated with cladded-wear plates, hence was used only to present various alternatives available to hard-facing.

The research carried out by Dasguta et al.explores the wear as well as erosion of tools being employed on the ground during the process of mining as well as agricultural industry. It presents a general picture of techniques applied in surface engineering’s ability with the aim of improving the tribological execution of various types of equipment. To that effect, many case studies with the aim of evaluating various hard-facing techniques have been analyzed and assessed. The paper presented here therefore was very instrumental in the determination of necessary category of hard-facing method that is supposed to be undertaken considering the conditions of operations as well as monetary constraints.

Coatings and Consumables for Improved Wear Resistance

In the assessment of experimental trends of composition as well as variables wear-process for hard-facings of weld deposited by abrasive wear-resistance as conducted by Garret et al. (1986), categorizes various kinds of wear as well as investigating the various material’s strength that are applicable to processes of hard-facing. The evaluation in the article is based on the micro-structure material of hard-facing of alloys or elements applied. Therefore, the information provided by this research study delves into in-depth analysis of the chemical composition together with micro-structures as compared that to the one that was needed for this study. Nonetheless, it presented very crucial information for the establishment of effects of wear on materials on the surface.

According to Kingsbury, on metal and alloys wear resistance investigated fundamental wear properties of various materials that was useful in the initial determination of wear properties of different components prior to being hard-faced. Also, it was equally applicable in the determination of the most suited hard-facing type for a given an application in comparison of an abrasive material with the one selected for hard-facing. The study also analyzed various components types of wear as well as techniques applied to reduce wear of the materials which as useful in the isolation of wear type on different parts of the dragline bucket. The research study facilitated the identification of other techniques of wear reduction that promoted the understanding as well as evaluation of minimization of wear types being employed currently in a given mining equipment piece. When these methods are compared to hard-facing approaches, then hard-facing benefits is easily identifiable and quantifiable. Whilst the book presented here fails to particularly focus on the application of hard-facing techniques, it details fundamental premises which is aimed at wear minimization techniques.

Following hard-facing fights wear-in-oil sands operation carried by Llewellyn and Tuite,  investigated specifically the key role played by surface engineering when surface wear resistance as well as productivity are increased. Included in the research is the notable reduction in the costs of repair along with costs of replacements. Even though the article fails to relate directly to mining of coal, the processes of welding applied on the equipment as well as its abrasive materials exposure implies that the shortcomings and benefits of the systems are deemed relevant.

Mega and Fabshield, of weld-surfacing keeps coals on-line analyzed the subsidiary of BHP that is recently using welding mechanisms on its heavy-mining equipment like hammer-mills as well as dragline buckets. The study also details out financial savings alongside ways of improving service life. The research paper has investigated gains made by increased productivity due to techniques of weld hard-surface and has facilitated the identification of costs of labour being considered as significant saving following the application of hard-facing technique. The research paper was not used entirely since it only a brief discussion on the key features that is related to the thesis prior to delving into the welding-composition bit of hard-facing.

Looking at the milled-tooth hard-facing as found at https://www.geodiamond.com/tool/cs_feats.htm which provides an additional area in the industry of mining where hard-facing is being demonstrated is where drill-bits as well as related items are found. Detailed report in the website are various hard-facing types together with its placement on the bit to ensure that the drill possesses particular properties. The website highlighted certain technologies like self-sharpening drill-bits as well as increased wear-resistance. The data presented in the website was very crucial in the establishment of hard-facing types applied on metal as well as the benefits that can be possibly realized. Even though, the website presented another hard-facing example, it was deemed as minor relevance to applications of hard-facing found in the mining industry.

Chemical Composition, Microstructure, and Wear Properties of Materials

According to industry guide to hard-facing for wear control, that is Welding Technology Institute of Australia (WTIA), 1996 which facilitated the delivery of this technical note which initially examined the health as well as safety facets of hard-facing operations and continued to further identify various types of wear. It discusses the best picking criteria of the most appropriate process of hard-facing and useful in the determination if a technique recently applied is the most appropriate. Further, it details typical hard-facing patterns for examination purposes as well as the analysis of economics of hard-facing and other several bigger issues well captured in the thesis hence believed to be very extensive and sufficient suitable for various applications.

Surface mining practice is a technique applied during the extraction of coal reserves in layers found around the surface of the earth and one of such technique employed is known as Open-cast mining technique. Overburden-stripping the instrumental exercise carried out in open-cast mines to eliminate the formation that is overlying. As a result of economic benefits, draglines are primarily utilized in this type of mines for the elimination of the overburden. A dragline attains the earth-moving approach using the hoisting, dumping as well as dragging actions of the bucket suspended from the boom. Consider the figure 1.1 which presents an illustration of a dragline operating in an open-cast mining.

In fact, a dragline machine fundamentally comprises two major categories as upper as well as lower constructions. Walking mechanism together with metal chassis are contained on the lower area whereas upper area contains drives as well as operator-cabins, excavation alongside haulage elements like chain, bucket, metal-rope as well as boom. An operator is always at the frontline and in charge of performance of the earth mover. Therefore, the person who operates dragline is in full control of the independent-swing, mechanisms of drag and hoist useful in the excavation as well as lifting of soft rock or pre-blasted found in the pit hence dumping it on spoil-pile adjacent to it.

At the time operation of dragline is carried out, external factors normally affects the affects the stripping performance hence making these factors categorized into two major classes, namely mine-planning factors as well as operational factors. Mine-planning factors majorly suitable for subjects like dragline selection as per geometry of excavation and site blasting criteria determined by the dragline’s dig-ability whereas operational factors include dragline’s availability, skills employed by the operator, bucket-load, program of maintenance, cycle-time and working parts fatigue life.

Utilization of dragline is popularly used different open-cast mining in various countries. Actually, in America only where 101 dragline units having bucket capacity that ranges from 30 cubic metres (40 yd³) to about 108 cubic metres (140 yd³) are applied in fifty-six open-cast mines with about 40 per cent of the total overburden eliminating operations in open-cast mining and is attained by the draglines. The percentage employed in this case is estimated to be equal to 1.5 billion cubic metres, which is 1.9 billion yd³ eliminated spoil per annum (Wardeh, 2018).

Fundamental Premises and Wear Reduction Techniques

A part from America, other foremost countries that utilizes dragline comprises of South Africa with twenty five units, Australia with sixty one units, India with seventeen units and Canada utilizing twenty two units whereas in Turkey, 8 units of Turkish coal-enterprises as well as one 1 unit in its private sector, totaling to 9 units of dragline being used several open-cast mining. The mines schedule of production is directly affected by the operations of popular earth-movers and dragline and therefore, negative factors realized there interaction of bucket formation needs to be detected and is very essential in operational efficiency of dragline.

It should be noted that draglines are many earth-moving machines that are commonly being used in open-cast mining in stripping out the overburden that normally cover the surface of the coal as indicated in figure 1.3 below. In fact, in the field of excavation for several decades, draglines have provided many historical records. In the year 1904, John W. page discovered the first dragline and founded a company known as Page Company which later formed a merger with the Harnischfeger Corporation bearing a single name commonly known as P & H in the year 1988. Marion-Steam Shovel as well as Bucyrus equally formed a merger under one single name of Bucyrus. Currently, Bucyrus as well as P&H are commonly known globally to be the manufacturers of dragline.

Figure 1.3 Dragline used in Stripping a Coal Mine

The system of dragline based-stripping is believed to be bringing economical savings of up to about forty percent in comparison to the method of shovel-truck. The figure 1.4 below indicates the changes in relative unit cost for various stripping ratios, dragline economical advantage as compared to the system of shovel-truck. Following the draglines production usefulness, one hundred and forty two units of dragline having larger bucket capacities as thirty cubic metres (40 yd³) are being used in about 69 mines across the globe. The working capability of these massive machines is believed to greater than ten-thousand service hours as well as several machines having one million type or greater production capacity. The table below, therefore provides for prevalence on the utilization of dragline in an open-cast coal-mining as per various countries.

Figure 1.4 the economical comparative analysis of Dragline and Shovel-struck 

Mining technique applications is the standard measure that determines the utilization of different draglines having various arrangements. Characteristics of dragline, production targets of mines, coal together with overburden-thicknesses, design of blasting, loose-material strength, area formation stability, skills employed by the dragline operator, coal-seams numbers as well as geology are some of the notable factors that can determine the technique type to be applied.

Table 2.1: Global country production of coal and dragline mine’s output

Having carried out the method specification, length of the pit as well as its width are needed to work out for the operation of dragline. In the applications of dragline mining, dimensions of working pit normally ranges from three to three thousand metres in length whereas that of the width ranges from twenty five to sixty metres (Kennedy, 1990). The dragline pit’s length is affected various factors like human based-handicaps, changes in geological as well as topographical effects. Considering pit width on the other hand, is presented as per the properties of formation, specifications of draglines like radius of dumping, rate of movement, maneuverability as well as parameters of design such as height of the pit alongside pattern of blasting.

Hard-Facing Benefits and Quantifiable Productivity Improvement

In the Australian stripping mining which is based on the utilization types, dragline mining technique uses seven representative methods with geology being more complicated as well as having significant amount of overburden eliminated in comparison to the United States alongside European stripping-mines. The methods presented here can be referred as simple-side cast, split-bench also called deep stripping, and standard extended-bench having an advance-bench, single-high-wall and double-low-wall multi-pass, extended key-cut as well as double high-wall and single low-wall multi-pass. Tandem-dragline technique is a technique that facilitates two dragline to function together hence applied in European as well as United States mining. Simple side cast is commonly used as dragline stripping technique as far as surface coal mining is concerned.

Longitudinal excavation is normally employed in the initial stages of operation of simple side casting technique and is also referred as box-cut. The introductory excavation is achieved by creating an initial-space for overburden casting. Once box cutting has been carried out, the operations continues in an orderly manner where digging as well as dumping of the overburden pegged at an angle of ninety degrees in a rotational movements. Because the dragline facilitates the completion of side casting following the pit-route, it goes through the immediate parallel-pit.

Figure 1.5 showing Simple side casting

Worldwide competition makes the companies found in the mining sectors to scale up their productivities by managing their capital as well as operational investments. The determination of appropriate mining technique together with economic pre-evaluation, scheduling as well as risks on security gain certain benefits in measuring the accuracy of plans which is either long-term or short-term in a dynamic mining sector. The technological establishment, simulations often indicates achievable outcomes in an environment that is considered virtual hence assists in the mechanism of making of decision for operations of dragline.

Therefore, this section presented will review past computer based studies that relates to the productivity of operations of draglines machines. In the current decades, several research work relating to working efficiency of dragline have conducted giving three topic sub-division; scheduling operations and planning of mines, productivity research relating to loaded dragline parts as well as simulations of virtual reality thereby increasing operator skills.

Studies that are computer-based have been carried out to make use of either short-term, mid-term or long-term dragline planning of mines as well as work schedules for many years. Following the previous studies, an integrated computer simulation-model having DSLX as a computer language was established to facilitate the optimization of operations of draglines. A geological model that is 3-dimensional with the help of geological database system was established. Multi-seam operations which were considered complex as well as unique dragline techniques were said to have been scheduled and as well simulated in the model.

This is another area that presents a facet for dragline productivity where dragline operator is trained in an excavation environment that is virtual. In fact, an operator of dragline that is not experienced is a daunting task and is required to take a period of six month training sessions to enable a dragline operator to become proficient. Therefore, this condition can lead to a financial loss amounting to approximately 2,500 dollars per hour. Further, that kind of an operator may lead to environmental hazards as well as machine risks in the site of mining.

Cladded-Water Plates and Dragline Buckets

This forms the third research topic for dragline productivity which is based on dragline front-end parts at the time of excavation as well as their impacts over the productivity. Ideally, a dragline is an earth-mover that is being operated by its long as well as heavy-boom in a wide range of curvilinear region. Therefore various amounts of forces applied as well as inertias used to unique parts of the machine at the time of digging, revolving, hoisting and dumping cycles makin dragline being managed in a manner that maximum payload amount needed is able to be carried within reduced time of cycle without failure which is catastrophic in nature or damaged caused by the mechanism. Because these kinds of failures as well as damages may lead to long-term breakages, production loss as well as time loss. Therefore, investigation as well as simulation carried out on the parts that loaded of the dragline are very critical to facilitate the effects analysis over dragline execution.

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