Mining ropes

Securing the safety of mining ropes is an important topic. The visual inspection of wire ropes is necessary to prevent a catastrophic failure, as well as determining and extending the safe operational limits of mining ropes. The situation in all mine shaft systems with rope operation is known usually it is necessary to visually check the ropes for external damages on a regular basis. 

Safe using of the various lifting machines like cranes, mine hoists, air rope ways, elevators etc. depends on steel wire ropes durability. Ropes are non repairable components of the machines. That is why the ropes worn or failed must be changed. 

The INTROS Flaw Detector is certified by the Russian State Standard Service (GOSSTANDART) as well as approved by the Russian State Mining and Technology Safety Inspection (GOSGORTECHNADZOR). It is used to inspect mining hoist and crane ropes. Fig. 5 illustrates the INTROS use at the mining hoist of an Ural ore mine. The previous model of the instrument, MDK-11 was used to inspect ropes of the air rope ways in Caucasus and Kazakhstan in 1996. Fig. 6 shows the INTROS MDK-11 inspection of 45 mm skyline rope in Almaty, Kazakhstan. 

R. Pryde New Developments in Non-Destructive Testing of Hoisting Ropes.-Mine Hoisting 96, International Scientific and Technical Conf, 8-10 Oct. 1996, Gliwice, Poland, in 2 vol., vol. 2, pp. 22-24. 

Rope location Skip hoist Install date 11/02/96 Mine VGOK Shaft Central Unit INTROS MDK21... 

Otter (or Paravane). A protective underwater device which, when towed with a wire rope from a fitting on the bow of a ship, rides out from the ship s side and cuts the cables of anchored mines. The mines then rise to the... 

For ROPE applications to tar sand mining, economic projections were published for capital costs and operating costs. Total capital costs were estimated at 53,336,000 and annual operating costs were estimated at 9,683,000. For the estimation of capital costs, direct field cost was estimated at 35,558,000. Other capital costs were based on percentages of that estimate. These cost estimates were based on mid-1989 dollars (D13089C, pp. 242-243). 

Trisubstituted organotins are useful biocides in agriculture and industry. They function as fungicides, bactericides, antihelminthics, and rodent repellents (WHO 1980). Tributyltins are used as antifoulants in marine paints but are restricted by the Organotin Antifouling Paints Control Act (June 16, 1988) which limits the type of vessel on which these paints can be used and sets acceptable release limits (U.S. Bureau of Mines 1989). Bis(tributyltin)oxide is used as a preservative for wood products, leather, ropes, fabrics, and paper. 

Asbestos constitutes several types of hydrated silicate mineral fibers. The types of asbestos, their chemical compositions, and CAS Numbers are presented in Table 3.8.1. These substances occur in nature in rocks, silicate minerals, fibrous stones, and underground mines. This class of substances exhibits unique properties of noncombustibility, high resistance to acids, and high tensile strength for which they were widely used in many products, including floor and roofing tiles, cement, textiles, ropes, wallboards, and papers. Because of the health hazards associated with excessive exposure to asbestos, the use of these substances is currently banned. 

The vicissitudes of the mining industry in the United Kingdom in the 1920 s and 30 s are well known. The headlines of the Cannock Advertiser bear witness to the fact that the three-day working week was prevalent in the Cannock Chase coalfield. Even at such times, the pit shafts and ropes had to be examined daily, and, in the earlier days, the horses had to be fed. Consequently, compared with others, the job of a winder was relatively secure, and the winders worked seven days a week all year round. On many a Christmas morning, the Bourne children opened their presents when their father was at work. Arnold Price, for many years Jack Bourne s work-mate, recalls that, for eleven consecutive years, he worked on Christmas Day. 

Another technique used in combat is the explosive line charge. The line charge is a cord or rope of explosives that is fired across a suspected minefield. The explosives are set off to detonate or disable nearby mines and thus clear a path. Line charges have been used since World War II and are still being improved today. 

Wire ropes are used extensively in the mining industry to help hoist equipment. Mine workers also depend on this rope for their safety. Wire rope undergoes both corrosion and abrasion, which will degrade the mechanical properties of the wire and thus reduce its load-bearing capability and cause it to fail. 

A statistical study of mine-hoist wire ropes showed that 66% of the ropes exhibited greatest loss in strength in the portion of the rope in contact with the shaft environment during its service life (26). The Mine Safety and Health Administration (MSHA) of the US Department of Labor requires that wire ropes in service be visually examined for structural damage, corrosion, and improper lubrication or dressing (27). MSHA also requires performance of careful nondestructive testing (NDT) every 6 months and cites one instance where a contractor reported that four ropes were in acceptable condition for use in an elevator shaft. However, less than 6 weeks later, one of the four 12.7 mm (0.5 in.) diameter ropes broke and another was severely corroded with several broken wires (28). 

Wire ropes within the mining industry are routinely replaced every 18-36 months depending on environmental conditions and use over time. The wire ropes are made of carbon steel however, because of their susceptibility to corrosion and wear, stainless steel and synthetic fiber ropes are becoming more widely used instead of carbon steel ropes (25). 

The corrosive environment of the mining industry limits the life span of the processing equipment and as a result decreases production and endangers lives of personnel. Some examples of mining equipment prone to corrosion are (i) wire rope (ii) roof bolts (iii) pump and piping systems (iv) mining electronics and (v) acid mine drainage. 

The safety technology of head rope replacement in large friction hoisting mine... 

In friction lifting mine, Hoisting System run by the friction between the head rope and the friction wheel, the safety and reliability of the first line directly affect safety. According to coal mine safety rules , the head rope needs to be replaced every 2 years, if broken wire, corrosion, wear is overrun, rope diameter shrinkage exceed limit, and so on appeared on the head rope, it must be replaced in time, even if less than two years. 

The rope exchange vehicle is a collection of a pull system, and rope winch, protection system and power system, able to apply all replacement, maximum release speed can reach 0.5 m/s, greatly save the rope release time. When the method of exchange rope in appropriate cases, can exchange rope work done within 12 hours in mine, which 1000 m deep and the head rope more than 40 mm in diameter. And release rope are implemented by high-quality friction liner, old and new head line tolerance status the same as the friction roller, do not damage the head rope. As shown in figure 3. 

Jia F Y, Li Z J, Wang Y B Sun J X. 2008. Analysis on safety and reliable braking of sliding rope on frictional hoist. Coal Mine Enginering (5) 99-100. (In Chinese). 

Jia F Y, Bi J M, Bi S H, Chu L Wang Y B. 2008. SLT Cage Path Rope Online Detect Automatism Modulate Device. Coal Mine Machinery 29(4) 117-118. (In Chinese). 

Ma J. 2008. Distribution of wire deformation within strands of wire ropes. Journal of China University of Mining and Technology 18(3) 475-478. (In Chinese). 

Ma K C Jia F Y. 2011. Replacement Method and Safety Analysis on First Rope of Mine Shaft Hoist. Coal Science and Technology 39(9) 73-76. (In Chinese). 

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