Background:

The General Electric Lighting Division produces a variety of lighting products. At its glass plant, GE produces borosilicate glass for over a hundred different lens covers and reflectors.

During glass production, each day more than 650 bounds of mostly borax and salt dust are collected. GE uses the recovered dust as a minor ingredient in making new glass, but working with the dust is difficult.

Challenge:

GE initially used a pelletizing process to prepare the dust for recycling. But after each batch run, the equipment had to be washed to prevent salty residue from corroding the pelletizer during idle periods – which was fairly labor intensive according to Henry Dietzel, Manager of Furnace and Facilities at GE’s Somerset plant.

Plus, the process introduced water into the dry material handling system, which meant the pellets had to be dried before they could join the production cycle.

Solution:

After seeing briquetters in action at a nearby Kingsford charcoal plant, GE saw the potential for briquetters in their own operation. They sent captured flue dust to K.R. KOMAREK Inc.’s research lab for a test, which showed that the dust could be pressed into small briquettes without water or another binder.

Dietzel says that the positive test results at the research lab convinced them to move forward. “We knew KOMAREK was a leader in the briquetting equipment field and we decided that was the direction we wanted to head.”

General Electric installed a KOMAREK low-speed roll-press briquetter, which forms chalk-shaped sticks through the use of two vertically opposed, counter-rotating rolls. A screw feeder in the briquetter’s inlet feed hopper delivers dust into the rolls’ nip region, where the rolls come together. As the rolls turn, the upper and lower pockets join to form each briquette-shaped cavity. Pressure applied to the dust as the pockets close creates the stick-shaped briquette.

Adjustments were made to accommodate differences between hot dust and dust that had cooled. KOMAREK made new rolls that included two rows of pockets in a staggered pattern and that were about half the original briquette size. This allowed the rolls to produce briquettes at various roll speeds, which in turn matches the briquetting process with the captured dust volume.

Results:

Since installing the briquetter, Dietzel said operators have spent less time attending to the dust handling equipment. “It has reduced the number of work-hours that we put in to recycle dust…and it has eliminated the environmental concerns we had when cleaning the pelletizer with water.”

According to Dietzel, “the briquetter has met all of GE’s expectations.”

Background:

The Linwood Mining and Minerals Corporation’s Buffalo Plant mines approximately two millions tons of limestone per year.

Adding a new rotary kiln more than doubled lime production capacity at Linwood Mining and Minerals Corporation’s Buffalo plant. But it also raised the problem of what to do with a greatly increased output of fines.

Challenge:

Linwood realized landfilling waste fines at rates of up to 100 tons/day wouldn’t be a good long-term solution. According to Assistant Lime Plant Manager Dennis Jones, “the minute we started planning the kiln expansion, we knew we’d get into trouble with the amount of fine output.”

Solution:

Linwood previously considered briquetting the fines for sale, but it wasn’t a viable option because of the relatively small amount left over. Adding the new kiln finally made it feasible. Jeff Dahl, Plant Manager, said “briquetting always looked like the only way to reclaim fines in this quantity, and the only company we saw that could supply the kind of equipment we needed was K.R. KOMAREK Inc.”

Linwood sent several barrels of calcined fines to KOMAREK’s dedicated research lab for testing on special laboratory versions of KOMAREK’s production machines. Tests confirmed that the material formed good briquettes, with no need for binders.

Guided by the evaluation results, KOMAREK proposed a roll-press briquetter engineered to produce an oval-shaped briquette at throughputs of up to 10,000 lbs (4,500 Kg) per hour. The briquettes were formed with two counter-rotating rolls, vertically opposed and fed from one side by a horizontal infeed screw. The machine also featured a cantilevered design with rolls mounted outside one end of the machine, which allows for quicker, easier roll changes – another KOMAREK recommendation because the abrasiveness of lime requires periodic replacement of worn-out rolls.

Results:

Dahl explained the primary goal with the briquetting solution was to reduce the cost of waste. “If 20 percent of our material comes through as fines and gets dumped, then we’re throwing away 20 percent of the cost of mining the stone, crushing, screening, handling and calcining it. That makes those fines too valuable to end up on a landfill. We figure this system paid for itself within a year or so.”

With the help of KOMAREK’s automated roll press briquetter, Linwood not only dodged the landfill scenario, but more importantly, gained a way to keep new fines in the product stream at full value.

Background:

Like other steelmakers, National Recovery Systems (NRS) faced tightening EPA regulations and landfilling restrictions combined with rising scrap costs.

While mill wastes such as dust, slag and scale have long been recovered by sintering, Basic Oxygen Furnace (BOF) sludge presented a difficult challenge to turn into a reusable form.

Challenge:

Steve Milter, President of National Recovery Systems, explained that “BOF sludge is rich in iron, carbon and other recoverable elements, and represents the largest waste stream from a BOF operation. It’s the biggest part of a steelmaker’s landfill problem, but it also gives us the biggest potential for recovery of valuable materials.”

But unfortunately, even after thickening to 85 percent solids by centrifuge dewatering followed by air drying, sludge remains too wet to allow charging into a BOF, which typically left landfill as the only alternative.

Milter knew that briquetting was the key to recycling. “When sludge is dried enough to be charged into a BOF, it becomes a fine, dusty powder that would be blown away by updrafts long before it reached the molten steel.”

Solution:

K.R. KOMAREK Inc. designed and built roll briquetters to fit NRS’ specifications. The machines use two horizontally-opposed, counter-rotating rolls with half-briquette pockets machined on their circumference faces. Both rolls are indexed so the pockets on opposing rolls match as the rolls turn, closing to form whole briquette-shaped cavities as both halves pass through the roll centerline.

Due to the highly abrasive nature of iron oxide wastes, the briquette rolls are also made of a proprietary wear-resistant alloy developed by KOMAREK. The rolls consist of 18 separate segments, which are independently clamped onto the rolls. This design greatly facilitates roll changes when the pockets become worn out. Milter explains that replacing all the pocket segments takes only about eight hours, so lost production time is easily absorbed.

Results:

The use of briquetting for conservation and recovery reduces outlays for scrap and avoids costs associated with landfilling the sludge and other oxides – which can easily costs tens of millions of dollars per year when factoring in costs to solidify and transport to remote locations explained Milter.

KOMAREK offers comprehensive plant system audits that can save you money. Conducted by our highly-trained staff, our audit service includes:

• Evaluation of material flow, handling processes and machine operations to increase product quality
• Review of part wear and assessment of any needed replacement parts to lower maintenance and repair costs
• Recommended maintenance to decrease downtime and improve productivity

Yes. We have over 800 machine installations worldwide – from North America, Central America, South America, Europe and Asia to the Middle East and Australia. KOMAREK can supervise the installation and initial production of your new machine.

KOMAREK has a dedicated team of engineering and service staff who work with you to determine if binders are needed, and if so, what kind to use, plus the best briquette or compact/granule size to fit each application.

Once equipment specifications are determined and finalized, parts are manufactured in KOMAREK’s modern U.S. plant that includes in-house machining of critical components, such as heat-treating and polishing, to ensure the highest quality and reliability.

Yes. In addition to designing and manufacturing custom replacement parts for all KOMAREK machines, we also design and manufacture replacement parts for many other manufacturer’s briquetting and compacting/granulation machines.

Depending on the roll tire complexity and roll material needed, typical production for replacement roll tires or segments is 10 to 12 weeks.

Subtle signs like increases in machine downtime or decreases in product quality are signals your briquetting or compaction/granulation plant operations aren’t running as efficiently as they could be – which can translate into increased operational costs.

For more information about KOMAREK’s plant audit which can identify potential issues before they become problems, contact us.