Date: October 1, 2008 

 (Finalized: January 13, 2009) 

Subject: Site Visit – Interceramic, Garland, Texas 

Clay Ceramics Manufacturing NESHAP 

EPA Contract No. EP-D-06-118; EPA Work Assignment No. 2-09 

RTI Project No. 0210426.002.009 

From: Richard Marinshaw 

To: Jeff Telander 

EPA/SPPD/MMG (D243-02) 

U. S. Environmental Protection Agency 

Research Triangle Park, N.C. 27711 

 I. Purpose 

 

 The purpose of this visit was to observe the ceramic tile manufacturing process at the 

Interceramic Inc. (Interceramic) facility and to collect information on sources of hazardous air 

pollutant (HAP) emissions and emission controls in support of the redevelopment of national 

emission standards for hazardous air pollutants (NESHAP) for the clay ceramics manufacturing 

industry. 

 II. Place and Date 

Interceramic Inc. (Interceramic) 

2333 South Jupiter Road 

Garland, Texas 75041 

 September 11, 2008 

 III. Attendees 

 

 Interceramic 

 

 Jorge Duran, Plant Manager 

Telephone: (214) 503-4941 

Felipe Matan Merino, Technical Director 

Telephone: (214) 503-5500 
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 U. S. Environmental Protection Agency 

 Jeff Telander 

 Telephone: (919) 541-5427 

 RTI International 

 

 Richard Marinshaw 

 Telephone: (919) 316-3735 

 IV. Discussion 

 A. Background 

 The Interceramic facility in Garland, Texas manufactures ceramic wall tile and trim. 

The plant has an annual production capacity of 31.5 million square feet of tile. The primary raw 

materials used to make clay bodies at the plant include ball clay, plastic-type clay, sand, calcium 

carbonate, and nepheline syenite. Glaze materials used at the plant include frits, metal-based 

stains, zirconium silicate, calcined alumina, kaolin, quartz, and hematite. 

 The Garland facility has a total of five roller kilns. However, due to market 

conditions, only two of the kilns are currently in operation: one “field” tile kiln and one kiln for 

firing trim tile. The plant operates 24 hours per day, 7 days per week. The kilns are operated 

around the clock; the ball mills and spray dryer typically are operated only 3 days per week. 

When operating at capacity, the plant employs about 230 persons, but currently there are only 

about 150 employees. 

 

 B. Process 

 The processing steps used at Interceramic include raw material storage, body material 

and glaze preparation, tile pressing, drying, glazing, firing, inspection, and packaging. The 

following paragraphs describe the process in more detail. 

1. Raw Material Storage 

 Raw materials used by Interceramic are received by trucks. The materials are emptied 

into hoppers and conveyed to silos for storage. 

2. Preparation 

 From the storage silos, the raw materials are deposited onto a weigh scale and 

conveyed to the grinding area. There, the materials are mixed with water and ground in one of 

three ball mills, forming a slip. A typical grinding cycle lasts about 5 hours. From the ball mills, 

the slip is pumped to one of two blungers for further mixing until it is ready for the spray dryer. 

From the blungers, the slip passes through vibrating screens to remove oversize material and is 

pumped to the spray dryer. The purpose of spray drying is to produce a powder of uniform 
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particle size that can be poured and spread uniformly across tile dies for pressing. Otherwise, it 

is difficult to meet the size and quality specifications for larger ceramic tiles. 

 In the spray dryer, the slip is sprayed into a drying chamber, where hot air flows 

countercurrent to the slip spray and dries the slip, forming a fine powder. The powder falls to the 

bottom of the dryer and onto a conveyor. The spray dryer is fired with natural gas. The dried 

material discharged from the spray dryer is conveyed to storage silos. As noted previously, the 

spray dryer currently is operated about 3 days per week. 

 During glaze preparation, the frits, calcium carbonate, and kaolin are combined with 

water and ground in a ball mill to create the glaze mix. The glaze mix is then stored in large 

plastic and metallic containers until ready for use. 

3. Pressing and Drying 

 In the pressing area, the spray-dried powder is conveyed from the storage silos to 

hoppers that feed the hydraulic presses, which form the unfired “green” tiles. A conveyor belt 

transfers the green tiles from the presses to a continuous tile dryer. Any defective green tiles are 

crushed and recycled back to the process. The original tile dryers, which are fired with natural 

gas, operate at a temperature of about 400°F. In May 2008, Interceramic installed a radiative 

heating dryer, which operates at about 350°F and uses only about 22 percent of the energy 

required by the older tile dryers. Waste heat from the new dryer can be used to preheat the 

combustion air for the kiln. In addition, with the new dryer, the total firing cycle has been 

reduced from about 3 hours to 45 minutes. 

4. Glazing 

 From the dryer, the dried tiles are aligned and brushed before being sprayed with 

water for glaze application. Glaze is applied to the tiles by the curtain coating (waterfall) 

method, which provides a uniform coating over the face of the tile. After glazing, the tiles may 

be directed to a roller printer that applies patterns or designs to the tile faces. The glazed tiles are 

then conveyed to a loading machine, which places the tiles on racks for transporting to the kiln. 

Excess glaze from the curtain coaters is recycled back to the process. 

5. Firing 

 The glazed tiles are transported to and loaded into a roller kiln. As noted above, 

although Interceramic has five kilns, only two are currently in operation. All of the kilns are 

fired with natural gas. After firing, the tiles are loaded onto racks and transferred to the 

inspection and packaging area of the plant. 

6. Inspection and Packaging 

 The fired tiles are inspected for quality control. The inspection of field tiles is 

automated. However, trim tiles must be inspected manually. Defective tiles are recycled back to 

the process, while the good quality tiles are stacked and packaged for shipping using an 

automated process. 
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 C. Emissions and Controls 

 Emissions from the kilns include hydrogen fluoride (HF), hydrogen chloride (HCl), 

sulfur dioxide (SO2), particulate matter (PM), and products of combustion. The PM may include 

HAP metals from the glazes. The kilns at Interceramic are not equipped with emission controls 

because it is not a necessary requirement per the emission testing results that indicate all is 

within environmental state regulations. 

 Emissions from dusty operations, such as raw material handling and transfer, are 

controlled with fabric filters. Because the plant uses curtain coating, there are no emissions from 

the glazing process. Emissions from the spray dryer are controlled with a wet scrubber. 

Interceramic recycles the wastewater generated by the scrubber.