MFM upgraded its primary crusher to a portable Bohringer Champ model 1200 horizontal-shaft-impactor, in part because of its roller grizzly arrangement.
The MFM Group of Companies (the company was originally named Mid Florida Mining) in Marion County, Fla., consists of MFM Limestone LLC and MFM Industries Inc. and was founded in 1964. At the beginning, the company produced absorbent clay products for agriculture and many other uses, including cat litter. In the mid-70s, the focus changed completely to cat litter.
“Today, 85 percent of our business on the cat litter side is private label, for stores such as Publix, Winn Dixie, Dollar General,” Elliott Mallard, president of MFM noted. “We mine and produce the actual cat litter clay. We’re predominantly in the eastern United States, but we do have some national accounts that we ship to. The cat litter business has been a good foundation for the MFM Group.”
Mallard got involved with the business in late 2006, when he and his consulting business were asked to do a geologic investigation of the limestone on the property.
“I found that the 720-acre site had in excess of 250 million tons of limestone reserves on it,” Mallard said.
The limestone is 97 to 98 percent calcium carbonate, which power plants can use for flue gas desulphurization. In addition, the company makes commercial grade aggregate for the concrete industry. Currently, MFM is under contract with Seminole Electric Power Plant, near Palatka, Fla.
“For the power plant, we supply crushed (minus 2.5 inch) limestone, road base which is DOT certified and commercial grade aggregate,” said Mallard. “As we get deeper and a little bigger, we’ll focus on making DOT- grade aggregate.”
Equipment upgrades were recently made through Great Southern Equipment and Sales in Savannah, Ga.
“One of the things that attracted the two companies to Great Southern is that they’re more of a one-stop shop,” Mallard explained. “Any needs we had, they could supply. Two years ago when I got heavily involved with MFM Limestone, we had undersized equipment, we had older equipment and we had just won a power plant contract and had to upgrade the facilities from overburden removal through mining and crushing and processing of finished limestone.”
Mallard had known Tommy Marks, Great Southern Construction Equipment’s vice president for several years, and he went to him for a quote when the time came to upgrade.
“Great Southern can come in and supply not just one thing, but everything from excavators and small mini loaders to articulated trucks, and they’re very competitively priced,” Mallard said.
The company upgraded its crusher operation. It added a portable Bohringer Champ model 1200 horizontal-shaft-impactor, in part because of its roller grizzly arrangement as its primary crusher and a Cedarapids 4040 secondary crusher which was installed on its wash plant.
“The Bohringer rejects anything minus two-and-a- inch, and anything plus two-and-a-half inch goes to the crushing chamber,” Mallard explained. “We have some very hard limestone nodules separated by some softer particles, and we can get a lot more through the crushing circuit if we reject the minus two-and-a-half inch. It immediately goes to the road base or to the power plant contract. Anything plus two-and-a-half inch goes to the crushing chamber, and then we can take that to our wash plant. We haven’t quite doubled our capacity by setting up the process that way, but we get the maximum production out of the crusher by that set-up.”
At the same time that they got the new crusher, MFM worked with Florida Processing Machinery on the design of a new 300 to 350-ton (272 to 317 t) wash plant, which the company then built and installed for them.
In addition, MFM acquired the first Kobelco 850 east of the Mississippi River, complete with an 8 to 9 cu. yd. (6.1 to 6.9 cu m) bucket. Other equipment includes a 480 Kobelco with a 6 cu. yd. (4.6 cu m) bucket, a 330 Kobelco with a 3 cu. yd. (2.3 cu m) bucket, two 115 Kawasakis with 9 cu. yd. buckets, a Caterpillar D9T and five Terex 40-ton (36 t) articulated haul trucks.
“Great Southern is a one-source supplier for all our needs,” Mallard said. “Any issue we have, we pick up the phone and we get immediate fixes and repairs. We’re benefiting from a longtime relationship that Tommy and I have had that has really helped us to get where we need to be.”
Gary Parker, vice president of operations, explained how the operation works.
“At the surface, there’s the Hawthorne Formation, and that’s what we make the cat litter from,” he said. “We’ve got 190 to 220 feet of Ocala limestone on this reserve. Ninety feet of that is above the water table, and we’ve got another 110 to 120 feet of limestone below the water table. So we’re working on getting a pit big enough so that ultimately it will be a three-phase operation where we’re doing clay, doing limestone above the water table, and then using a dragline to get limestone below the water table. We’re actively sourcing a dragline now, and we’re planning to get it during the next six to nine months.”
Parker explained that the Hawthorne layer can range from 25 to 60 ft (7.6 to 18.2 m). When it reaches 60 ft. (18.3 m), there is generally 30 to 40 ft. (9 to 12 m) of full reserve clay.
“The true way to test that you’ve got good full reserve clay is that it’s absorbent enough that if you touch it to your tongue, you have to rip it off your tongue — it’s that absorbent,” Parker said.
The wash plant operation is a closed circuit plant that creates three different aggregate products. Currently, it is set for 67,89 and 919 screenings for paver and block companies.
According to Mallard, MFM currently has in excess of 100 years’ worth of limestone reserves, an amount which is in the top five of reserves in the northern half of Florida. He also noted that they try to keep a two-to four-week stockpile for clay and limestone. That way, even with inclement weather, crushing and shipping can still be done.
“On the clay side, the excavator is loading directly into a contract haul truck that takes it to our cat litter facility,” Mallard said. “On the limestone side, the Kawasaki loaders feed the crusher and wash plant and fill outgoing trucks. Normally on day shift, we load the outgoing trucks and then operate the crusher and the wash plant on a back shift. The 115s have done a tremendous job for us and they’re a good piece of equipment.”
For the cat litter, the overburden is taken off and placed around the perimeter of the property. The clay is then excavated and hauled six miles to the cat litter facility, which includes a processing plant and bagging facility.
“I think with the old equipment, we probably had a maximum annual capacity of about a million tons,” Mallard said. “Now, I think our capacity is probably in excess of four million tons for total limestone production, and on the wash plant side, we’re at about a million and a half.
“This is the first operation I’ve ever worked at where we ran this type of equipment, but I really can’t say that I miss the equipment I was working with previously a whole lot, because the equipment we’re running seems to be very dependable,” Parker said. “The Terex trucks are great. We’re pulling probably eight- or nine-percent grades out here, and the older trucks came up pretty slow. There’s a noticeable difference, cutting about three minutes off of our average cycle time. At the end of the day, that’s a lot of money.”
Currently, there are 21 people on-site. CEG