CalPortland reconfigures a California site

Faced with the monumental challenge of moving a stationary jaw plant and feeder 1,000 ft. down a mountain, CalPortland Co. had two choices: Do it quickly, or do it right.

With more than 100 million tons of hard rock granite left to mine at its Rocky Canyon Quarry, operations manager Ben Marsalek knew he had to carefully consider the effectiveness of the methods used to mine. The decisions made would impact the company and the environment for decades – if not a century – to come.

After consulting with CalPortland’s internal engineering group, Marsalek and site manager Rocky Torgrimson calculated serious financial and energy savings by completely revamping its method of transporting blasted material to the crusher, with the main goal of reducing fuel consumption and man-hours.

“The whole purpose of this project was to set the quarry up for the future,” Marsalek says. “We [were] in phase two of a 10-phase mining plan, so we knew there would be a lot of years left mining at this site. We wanted to improve efficiency, and we knew that when we moved the crusher, we didn’t want to move it again. This plant will still be in existence well after we’re gone, so it was important to do this right.”

Eye to the future

CalPortland is a large building materials company on the West Coast of the United States that produces cement and construction material products.

The Rocky Canyon Quarry, located in Atascadero, California, has been in operation since 1985 and produces 1 million tons of material each year. The 200-acre hard rock granite quarry produces structural fill material, ready-mix concrete aggregate, road base and asphalt aggregate, 40 percent of which are sold commercially along the U.S. Route 101 corridor.

The stationary jaw crusher, a Pioneer 3042 from Kolberg-Pioneer Inc., was first put into operation halfway down the mountain in 1999. At that time, CalPortland used Cat 992D loaders to load material onto a conveyor, where it moved the blasted material down the mountain to be crushed and finished.

As the company mined more of the mountain, the need to move the eastside jaw location became clear. In 2013, CalPortland initiated a study to determine where the jaw needed to be located and the most efficient means of transporting material to that location.

The results showed an overhaul of CalPortland’s mining methods would have a serious impact not just on its bottom line, but to the environment as well. As a result, the company elected to move away from its original load-and-carry method and switch to a haul truck system.

With a strategy in mind, the company began its initial planning phase in June 2014. By January 2015, its capital proposal was approved. Construction began in August of that year, and the new system was up and running by January 2016.

Now, after material is drilled and blasted, it is transported using a Cat 988K loader to load two Cat 735C articulated haul trucks. The haul trucks travel a haul road to the company’s 100-ton Telsmith hopper, which has a 60-in. x 24-ft.-long vibrating grizzly that feeds the jaw crusher. From there, material is conveyed into a surge pile, which then goes to the finishing plant.

Overcoming challenges

One significant challenge the company faced was supporting the haul trucks on the mountain. To combat this, the team Marsalek and Torgrimson assembled had to engineer and construct a structural fill ramp for the trucks to drive on to dump material.

“We knew we had to construct some kind of retaining wall for trucks to drive on,” Marsalek says. “One option was a concrete wall, but that wouldn’t work for us. We knew from our soil reports and seismic studies that a poured-in-place concrete retaining wall was not economically feasible.”

The company chose to engineer and construct a three-sided Redi-Rock retaining wall with a fill behind it. The 30-ft.-high wall uses 22 layers of block, each block constructed with a hole in the middle. Using a geogrid, each block is then filled with backfill produced at the plant. Because the wall had to be inspected daily and tested for compaction, this step took the longest of all.

“Resources from the entire CalPortland Co. were used to construct this retaining wall,” Marsalek says. “The blocks were made by Mid-State Concrete Products, a precast company that buys its ready-mix from CalPortland. The backfill was used from fill material that Rocky Canyon produced, and the concrete for foundations that was placed by our construction group was from our concrete plants.”

When choosing where to reposition the jaw crusher, Torgrimson says they selected the location as close to the final elevation as they could get so they wouldn’t have to mine under it.

“Once we found that location, we had to drill and blast that area to make it a finished elevation,” he says.

Moving the jaw crusher also helped increase the company’s efficiency because the face of the mountain had moved away from the plant since it first began in 1999.

“Having so much distance between the jaw and the face of the mountain made it more difficult to keep up with the jaw with the existing load-and-carry scenario,” Marsalek says. “By moving the jaw and going to haul trucks, we have found we are much more efficient in keeping the plant fed at all times.”

Impressively, the company pulled off the feat with no outside contractors – just the dedication of its 11-person mining team and the construction group’s concrete crews for foundation pours. The plant was only down for two weeks while it was being moved.

“We engineered and constructed everything ourselves, all while maintaining production at the existing operation,” Torgrimson says. “We had to work around many challenges – from working in a very tight working space to scheduling work around moving the utilities, but our talented team was able to accomplish all of this and stay on schedule while keeping up with our production. That was very important to us.”

Environmental stewardship

Another important benefit of switching from a load-and-carry method was reducing a fleet of older Cat 992D loaders, which were Tier 0 and Tier 1 machines.

“The California Air Resources Board has instituted an off-road fleet replacement schedule for older equipment that all companies in California are having to plan and budget for,” Marsalek says. “We knew our current system of load and carry with the existing 992s was going to have to be addressed sometime in the near future, and having to move the jaw presented the perfect opportunity to reevaluate our methods and upgrade our equipment to meet future standards.”

It should come as no surprise that energy efficiency is an important goal for CalPortland. The company is well known for its environmental leadership and commitment to sustainability. In fact, CalPortland was recognized with the U.S. Environmental Protection Agency’s (EPA) 2016 Energy Star Partner of the Year – Sustained Excellence Award for continued leadership in protecting the environment through superior energy efficiency achievements. This was the 12th year the company received the award.

“CalPortland’s whole focus is to look at our operations and focus on what we can do to become efficient, conscientious and environmentally friendly,” Marsalek says. “Our big focus is efficiency. CalPortland is one of only a handful of industrial companies to be continuously recognized by the EPA for its focus on the environment. We realize we are a big energy user, which is why as a corporate team we are so dedicated to energy conservation.”

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Michelle Cwach is a freelance writer in Yankton, South Dakota. For more than five years, she has been covering the success stories of aggregate operations around the world.