Mining

A Galloway is a multi-decked work stage platform used to carry equipment during shaft sinking or refurbishment. It is suspended from the top of the mine shaft and can be raised and lowered as required during shaft sinking or shaft refurbishment operation. Since the multi-level platform can accommodate a large quantity of equipment of varying sizes and weights it is important to constantly monitor the weight of the Galloway to ensure it is not overloaded, which might result in failure of the system on which it is suspended.

Typically a Galloway is suspended by four wire ropes. In order to weigh the Galloway platform, a weigh scale system needs to be developed. The scale is comprised of very large load cells mounted on the end of the wire ropes suspending the Galloway. These load cells are in the form of large plates or rope attachments which are designed as tension load cells. The rope attachment envelop and it’s loading specifications is usually designed by a mine engineering company and this information is then handed to a custom load cell manufacturer. The load cell manufacturer designs the load cell to meet tight specifications within the design envelope specified.

The design of these Galloway load cells presents unique challenges because of the high factor of safety required, usually at least 10:1. In addition, the load cells require internal 4-20mA amplifiers which are then connected to the Programmable Logic Controller (PLC) on site. These load cells and their amplifier outputs must be precisely calibrated in special testing equipment with reference loads traceable to NIST standards.

Massload is a world leader in the design and manufacturer of high-quality Galloway load cells that are shipped to mining projects globally. Our experienced design, manufacture, and testing team are skilled at providing fast turnaround cycles for what is usually a critical project cycle.

Sinking mine shafts is a complex and critical task. Recent developments for soft to medium-hard rock includes the use of Shaft Boring Roadheader (SBR) technology, a machine suspended from wire ropes connected via sheaves in the head frame to winches on the surface.

Weigh scales systems are developed to measure the total load on the massive sheaves in the headframe. Measuring the load on these sheaves is not easy. One method is to design load cells to sit under the sheave mounting brackets called pillow-blocks. These pillow-block load cells are designed to fit under each side of the sheave assembly so the total load on the sheave can be monitored. The outputs from these load cells are converted to 4-20mA signals and fed into a Programmable Logic Controller (PLC).

Design and manufacture of these large pillow-block load cells and the accompanying electronic systems is a specialized task. Massload Technologies is a trusted leader in the custom design, manufacture, and calibration of sheave pillow-block load cells and associated instrumentation solutions for the mining industry.

Mine shafts frequently have a large girder positioned across the top of the shaft. This girder is the anchor point for hoisting items and material up and down the shaft. Installing a girder across the top of an underground mine shaft is a critical operation. The girder needs to be hoisted up and then pulled horizontally till it is in position.

Hoisting the girder presents special challenges when the anchor for the hoisting is the actual roof of the mine. In situations like this, it is common to design a rail system that is suspended from the mine roof by multiple anchor ropes and rock bolts into the roof. Attached to the rail will be a number of trolleys individually connected to electric hoists which are in turn connected to the girder. In cases such as this, it is critical that the roof anchor points are not overloaded.

Overloading of the roof anchors can occur when any of the hoists are unequally loaded compared to the other hoists. If this does occur, an anchor point may be pulled loose or out of the roof resulting in overloading the remaining hoists and possible failure of the operation. Therefore, it is critical that all hoists are loaded equally during the hoisting and pulling process. In order to monitor the loading of each individual hoist, a multi-point scale system needs to be designed. Such a system will comprise load cells mounted between each hoist rope and the corresponding lifting lug on the girder.

The preferred solution for such a scale system is a set of custom load pin shackles with wireless transponders communicating with PC-based software application used to monitor and adjust each hoist load during the operation. Unique challenges of such a system is the large factor of safety required for the load pin, usually 10:1, the wireless transmitter and software application. Massload Technologies is a leading provider of custom load pin solutions and has designed a girder lifting scale system for these unique conditions.

A mine surge bin is a temporary storage of raw mined material to facilitate converting the variable rate of supply into a steady flow based on the average production rate.

In underground mining, a surge bin may be suspended by wire ropes from the mine roof. This is usually done by hanging the surge bin on 20 or more ropes attached to flange at the bottom (or top) of the bin. This arrangement introduces unique challenges since it is critical to ensure that material entering the bin does not cause uneven loading on the wire ropes which may shift the centre of gravity of the bin. If this were to occur, individual wire ropes may become overloaded to the point where the anchor to the roof may fail. In order to deal with this issue, a scale system must be designed to monitor the individual loads of each wire rope.

Massload Technologies, a world leader in the design and manufacturer of custom scale solutions for the mining industry, has developed a unique under the flange through-hole load cell solution to monitor the tension load of each wire rope and feed this information via 4-20mA signaling to a Programmable Logic Controller (PLC).

Conveyor belts require continuous monitoring to ensure safe operation. Belt weight is a typical parameter that must be measured to prevent overloading. Belt tension is the ultimate parameter because when tension exceeds the overload capability the belt can yield.

Measuring belt tension can be done in several ways and usually involve load cells to measure tension. Although there are standard solutions available there are situations where a custom design is required. One such situation is where the belt is terminated at or near a wall and the tension measurement device must be very compact.

Massload Technologies specializes rugged standard tension links and in custom-designed solutions. Massload has developed compact tension load cells for mounting conveyor end drums to the wall face. Images shown are for standard tension links.

Weighing of aboveground mining vehicles is important for validating / re-calibrating on-board scale system and to verify the accuracy of the loader scale system. Properly calibrated mining vehicle scales is critical for avoiding overload, and increasing efficiency and throughput.

Massload Technologies has developed rugged high capacity aboveground mining vehicle scales based on axle weighing. These wireless scale systems are based on Massload’s durable high capacity load cells and use the Massload Advanced Weigh Scale Software which offers stop-go traffic light signaling, vehicle ID capture, wheel and axle weight totalisation and truck-in-truck out functionality. Tested and proven at Canada’s most remote mining location.

Underground mining vehicles include both mine hauling and utility vehicles. Light utility vehicles are used to transport people and equipment from central points to work sites. These vehicles also pull trailers loaded with equipment. These vehicles can be easily overloaded resulting in mechanical damage to transmissions or other parts. Weighing these utility vehicles is an important factor in equipment reliability and mine safety.

Massload Technologies has developed rugged underground vehicle scales for load checking and overload prevention and is rugged enough for weighing mine haul vehicles.