Making quantum leaps in development mining rates continues to be one of the main challenges for longwall operators. In an attempt to address this problem, Joy Mining Machinery has just released its Integrated Mining Machine (IMM), a machine incorporating automated cutting with installation of a full roof and rib bolting pattern.
Eventually, the IMM will form part of a complete, systems approach driven, Entry Development System (EDS). When the complete system, including a haulage component, is available the goal is to advance 300m in 15 hours of operation.
The IMM is designed to automatically cut a full-face width for a distance equal to most roof bolt centres, while simultaneously installing a full bolt pattern. Main advantages include the elimination of place changing and double pass inefficiencies; no pan or gathering assembly, and onboard protection for operators.
Tom Schwabenbauer, Joy director product development miners and haulage, said the development of IMM is the result of surveys around the globe with customers doing entry development and running longwall systems.
"We analysed their responses and came up with the central theme that during the course of longwall mining the bottleneck is trying to get the entry development to match up with the ever increasing rates of the shearers themselves.
"We wanted to take it one step further and determine where are we going to be in ten years time, where is this thing going to peak. We looked ahead and set our sights very high knowing entry development had to keep up with ever-increasing retreat. Based on that we set some lofty goals such as 300m of linear advance for entry development per day. Of course that has to do with the number of shifts the customer runs and the type of mine plan."
One of the mines with which Joy has worked closely is the Arch SUFCO mine. The IMM Coal Show machine was returned to Joy for testing/evaluation prior to being delivered to SUFCO sometime after the first of the year.
Speaking at MINExpo, SUFCO's technical services manager Wes Sorensen said the mine was seeking to achieve continuous cutting and bolting.
"We wanted 300m of advance per day, with the machine operating at 15 hours per day, cutting 75% of the time, mining at 3m X 5.5m."
Schwabenbauer pointed out that the IMM does not comprise the whole entry development system. Other issues such as haulage and the consumables required for concentrated bolting patterns, for example, have to be factored into a total systems approach, he said.
Later development phases for the IMM will be to develop a haulage component to complement the IMM.
"Our first step is to put the IMM concept into service and verify that our estimates are correct and once that's verified, we're going to be looking at things that go along with our flexible conveyor trains. That type of continuous haulage is proposed for the IMM."
What makes the machine unique is that it combines bolting and mining. According to Schwabenbauer the isolation of cutting from bolting allows operators to focus on bolting, and provides a systematic, controlled steady method, which should equate to overall increase in advance. An important operational paradigm shift is that the shuttle operator has radio remote control of the IMM tail and conveyor.
The bolters are Australian-made, a product of Cram Australia. Schwabenbauer said the acquisition of Cram two years ago allowed Joy Franklin to focus on developing a systems approach for the IMM. Design engineers were exchanged between Joy Roof Bolting Solutions in Australia and Joy Franklin to enable an exchange of concepts.
The IMM offers as many as four roof and two rib bolting assemblies that use large pre-stocked replaceable storage pods to supply materials. Operators are onboard and protected with a canopy and rib protection. The IMM works in heights of 1.5-4.5m and cuts width from 4.7-6.7m.
Other than the front head arrangement, the IMM is standard Joy componentry, including Joy Network Architecture (JNA) controlled, with selectable automated cutting cycles. Over 480 kilowatts are delivered to the cutter head.
A memorandum of understanding was signed at MINExpo for the first production version of the IMM to be delivered next year to the Matla mine in South Africa.