Plant Tours

Prairie Cement

Stand on top of the pre-heater tower and look east. Sage-brush prairie stretches itself up and across flat lands and small mesas from the place where the railroad tracks abruptly end to the horizon. From this height antelope and cattle bearing the brand of local ranchers are pencil-dots. At 314-feet the “tower” towers over its surroundings. Even the four concrete shipping silos are not so impressive looking down as they are from the ground looking up. Turn around and look west and the tower loses all bragging rights. This is the place in the world where the Rocky Mountains rise from the high plains. The prairie’s five thousand feet (plus 314) above sea level quickly becomes 12,000, with Greenhorn Mountain at the southernmost end of the Wet Mountain Range balding and snow-capped above timberline.

A VIEW TO A QUARRY

Though the scenery from the tower is impressive, just look a little to the south and straight down to discover the reason Grupo Cementos de Chihuahua (GCC) chose to locate its new state-of-the-art cement plant here. Thirty feet below the surface , a front-end loader, crusher and a series of conveyor belts run by an expert crew (more about that later) extract and process limestone from an open-pit and send it on its way to the 18,000 ton capacity limestone dome for storage. The high-quality limestone quarried here is part of the larger Fort Hayes deposit, and with little variation in composition it provides an excellent source of calcium carbonate for cement production. As the quarry expands, the movable conveyor/crusher system will process the rock from the face and transport it to the dome. On its way, the crushed limestone passes on a conveyor belt through a state-of-the-art CrossBelt online elemental analyzer that uses Prompt Gamma Neutron Activation Analysis (PGNAA), allowing both the crews in the loaders as well as laboratory analysts to see the chemical composition of the limestone real-time. The stone is carried to the top of the large dome-shaped steel structure whose diamond-shaped panels reflect sunlight adding a jewel-like sparkle to the otherwise gray industrial environment. Inside a stacker deposits it in a neat circular chevron pile. Vertical reclamation through the pile homogenizes the material before it’s dropped through the floor of the dome onto additional conveyor belts which carry it to the second stop on its journey, the raw-mill feed bins.

OTHER RAW MATERIALS

Trucks file in daily with sandstone from another local quarry, about 20 miles to the west. Both bottom-ash and mill-scale are recycled from local industry and provide efficient, cost-effective sources of aluminum and iron. These raw products are transported from either truck or rail unloading and transported through a series of covered conveyor belts which lace the southeast corner of the plant to the longitudinal storage building, or long-shed. The long-shed was the first structure to rise from the prairie floor, and what it lacks in height compared to the tower it makes up for in length, as the name implies. This structure can easily be seen from as far away as Pueblo West, (at least 10 miles as the crow flies) and served initially to remind area residents that a new industry was underway. Raw materials are reclaimed onto conveyor belts from the long shed and join the limestone in one of the five raw-mill feed bins. Even as this continual flow from unloading to proportioning bin takes place, efforts are always underway to locate optimum sources for all imported raw materials.

FROM RAW MIX TO CLINKER

Material from raw storage is proportioned via weigh feeders and transported to a four-roller, stories tall vertical raw mill, designed to produce 225 ST/HR of raw meal at a fineness of 12% retained on 90 microns. Hot gas from the pre-heater is captured to efficiently dry the material before it is collected in cyclones and the main bag filter and conveyed to the storage silo. The raw meal storage, or blending silo, with a 7500 ST capacity, stands just south of the tower and at a respectable half its height. There material is homogenized, proportioned and then transported via bucket elevator to the top of the imposing pre-heater tower. This five-stage, in-line, low-NOx system provides around 98% precalcination. The 4.35m x 51m two-support kiln with friction drive and tangential suspension is designed for a guaranteed production of 2900 STPD. The modern, multi-channel burner fires bituminous coal processed by a vertical coal mill. Clinker drops through the kiln hood onto an efficient 11-grate wide by 61-grate long movable cross bar cooler. This state-of-the-art pyroprocessing system is designed to provide the best efficiency and availability while achieving minimal emissions. Though the kiln rotates continuously these days, the crew remembers a cloudy late afternoon in January of 2008 which saw the long-awaited “first clinker” drop from the cooler onto the conveyor belt which terminates at the top of the clinker dome. After months and months of working in temporary trailers, trudging down long, sometimes muddy roads to work on and learn about these then skeletal steel structures, and braving both the cold high-plains winter winds and the 100-degree summer heat, the red-hot glow of the clinker was a welcome sight. Getting to this point had been no easy task, as testified to by the looks of satisfaction evident in the eyes of those watching through safety glasses setting just below already weathered white hard hats.

FINISHING TOUCH

Anyone who has walked the stairs that run alongside the conveyor belt from the cooler basement to the top of the clinker dome knows why it’s called the “Stairway to Heaven.” From the outside, this gigantic structure with its smooth white walls doesn’t look much larger than the limestone dome down the road, but step inside (when the kiln is down) and you’ve entered another world. The space is dark and enormous, with a capacity of 110,000 ST, five times that of the limestone dome. Mountains of clinker landscape the interior. Similar to the limestone, clinker drops through openings in the floor of the building onto conveyor belts and travels to the finish mill proportioning bins. This four-roller vertical mill is designed for 180 ST/HR at 3800 Blaine of OPC. Product from the mill is collected in a bag filter and transported to one of four 10,000 ST capacity storage silos. The silo area is a busy hub, with the shipping team unloading cement into both trucks and rail cars.

A ROOM WITH A VIEW

Rectangular glass walls extend from the south side second story of the administrative building and provide Control Room Operators a panoramic view of the rotating kiln from behind their long desk of monitors. Screens display mostly red and orange with an inside view of the kiln and burner. This is control central for the plant which is fully-automated with the latest proven automation technology available on the market. The main control system integrates a total of seven processors controlling all the plant operation and integrating all the traditional and “smart devices” from the field. A set of high-level optimization systems enable the facility to increase productivity, stabilize operations, increase performance, improve quality and integrate to global corporate systems. Across from the control room and also bordered by floor to ceiling glass walls an automated robotic laboratory staffed by highly qualified personnel operates around the clock to continuously insure product quality. The system includes automatic sampling, pneumatic transport and elemental chemical analysis for all process areas including kiln feed, kiln dust, raw meal, clinker and finished product. The large blue robotic arm swings tirelessly transporting samples from receiving station to mill to press to x-ray analyzer.

DYNAMIC GROWTH

GCC was founded in 1941 in Mexico, and currently operates three successful plants there as well as one in South America. They acquired a plant in Tijeras, New Mexico in 1994, and then a plant in Rapid City, South Dakota in 2001. Recent company growth has been dynamic, expanding to include distribution terminals, more than 80 ready-mix plants and a fleet of mixer trucks, and GCC Energy, a coal mine near Durango, Colorado. The combination of an abundant, quality limestone deposit as well as market need “cemented” their decision to build this Southern Colorado plant, among the newest in the country. GCC has just purchased Colorado Energy Recyclers and a vast supply of used tires. Future plans include incorporating alternative fuels, such as tires, for cost effectiveness, coal substitution and emissions reductions. With this newest plant, GCC has reached a production capacity of 5 million tons of cement production annually.

THE CITY IN THE DISTANCE

From the tower looking north, Pueblo lies about six-miles. This second-largest town in Southern Colorado began life as Ft. Pueblo in the mid 1800’s. The current city consists of four cities which were incorporated in the late 1890’s. Pueblo has a rich heritage, with populations including Italian, German, Slovenian, Hispanic, Irish and Native American. Families tend to live here for generations. Of those who leave for greener pastures in their youth, many eventually return “home” to settle. Pueblo boasts a unique blend of tradition and progression. The Pueblo Reservoir is one of the largest recreational areas in the state. Residents enjoy the new Riverwalk, the Sangre de Cristo Arts and Conference Center, and the Events Center at the Colorado State Fairgrounds. The smell of roasting chili peppers (locally grown in the large agricultural areas to the east) draws huge crowds to the Chili Frijole festival every fall and rightly so. Most here would agree that you haven’t had a bowl of green chili until you’ve had a bowl of Pueblo green chili. Driving through Pueblo on I-25 much of the landscape is industrial, with Pueblo being one of the largest steel producers west of the Mississippi. The locals know that this city built at the confluence of the Arkansas River and Fountain Creek provides a unique beauty. Cottonwoods, elms and willows shade beautiful parks in stately old neighborhoods. New neighborhoods provide unequaled views of the front-range. Green, irrigated fields quilt the eastern part of Pueblo County, with many families having farmed for this area for generations. To the west, beautiful canyons and pinon-juniper foothills provide stunning backdrops for Colorado sunsets. The weather is nearly ideal, with four distinct seasons and over 300 days of sunshine annually. Both Colorado State University-Pueblo and Pueblo Community College (PCC) provide excellent educational opportunities. Known as the “Home of Heroes” there are more Congressional Medal of Honor winners from Pueblo than any other city in the country. President Eisenhower said there must be something in the water here. It may be the water indeed, but almost all Puebloans come equipped with a sturdy set of boot-straps handed down through generations of hard-working people - strong enough to see them through the Great Flood of 1921, the economic collapse of the 1980s, and tenacious enough to see a thriving new industry rise from its southern prairies.

AN UNEXPECTED RESOURCE

Most of GCCs staff (nearly 75%) were hired from Pueblo and the surrounding area. Plant Manager Verne Stuessy refers to GCC Pueblo’s employees as “our most valuable resource and strongest competitive advantage”. Many, though highly skilled and with years of experience in heavy industry, had not worked at a cement plant. Through partnering with PCC’s Industrial Education Department, GCC developed a comprehensive training program with courses ranging from pneumatics and blueprint reading to PLCs and leadership. All new employees were hired a year or more in advance of actual production, and were trained both at PCC and on-site to the “expert level” prior to firing up the kiln. The crew was here as the plant was going up and they know it intimately. Housed in temporary trailers they spent hours studying equipment, machinery, processes and cement chemistry. Stuessy attributes nearly entirely the success of getting this green-field plant from prairie to production to his staff. He boasts their work ethic is unequaled. One department’s motto is a promise from our founding crews to future generations of GCC employees: “Building a Foundation as Strong as the Cement We Produce”.

A COMMITMENT TO EXCELLENCE

GCC Pueblo is managed and operated under a philosophy of continuous improvement, with little top-down management. Natural work teams meet on a regular basis to discuss and implement practices which will “continuously improve” plant operations. Employees are encouraged to achieve their highest potential, and are provided cross-training opportunities in all areas of plant operation. Recent awards and recognitions, including the Peak Award by Colorado Performance Excellence, demonstrate GCCs commitment to quality and high performance. The company is one of only two companies in Colorado ever to have received this prestigious Malcolm Baldridge Award, a fact made more notable considering the relative newness of the Pueblo facility. Community involvement is another priority for Stuessy and the Pueblo team. To date, GCC Pueblo has provided scholarships for area residents, participated in numerous charitable and sporting events, partnered with local Chambers of Commerce and school districts on many projects, and donated product to both the Historic Arkansas Riverwalk Project for expansion as well as to PCC for a new leadership training course. An ongoing commitment to excellence plus hard work and dedication by its employees have moved this “greenfield on the prairie” to a fully operational flagship cement plant capable of producing 1,000,000 tons a year, and despite tough economic times the outlook at GCC Pueblo remains positive in every direction.

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