Metso Supplies Grinding System to Swedish Mine
Boliden’s Aitik mine in Gallivare, Northern Sweden, is constructing a new concentrator with a grinding system supplied by Metso Minerals, York, Pa. Scheduled to begin production in 2010, the new concentrator will replace older equipment and help Boliden expand the processing capacity of the Aitik mine from approximately 18 million tons to 36 million tons of ore per year.

Metso’s contribution includes two AG (autogenous) mills and two pebble mills along with engineering, erection and startup services. Metso signed a two-year contract to maintain the grinding circuit, including spare and wear parts and tools. The AG mills, which measure 38 by 45' dia. (11.58 by 13.72 m dia.) are the largest ever supplied by the company.

Boliden, a large mining and smelting company with operations in Sweden, Finland, Norway and Ireland, produces copper, zinc, lead, gold and silver. According to Metso, the Aitik mine is one of Europe’s largest producers of copper and is a major producer of gold and silver.

Boilers Still Operating after 38 Years
An Encino, Calif., hospital has five Parker Boiler Co., boilers that have been in continuous operation since their 1969 installation. The Los Angeles manufacturer has recently retrofitted some of those boilers with low NO_X burner systems to comply with the South Coast Air Quality Management District Rule 1146.2. According to Parker Boiler, ongoing maintenance by the hospital’s engineering staff, including Freddie Avila, contributed to the longevity of the units.

Understanding Drying Methods
Convection, infrared, radio frequency and combination systems: A choice of drying methods allows processors to select technologies that best suit the process. A primer outlines the advantages and disadvantages of each heating method.

Calculating Heat Requirements
Two basic heat energy requirements should be considered in the sizing of heaters for a particular application.

Chilling Out with Sealless Pumps
Sealless pumps can reduce maintenance requirements and downtime, making them an attractive option for many chiller applications.

Thermocouples: A Thousand Shapes and Sizes
Every different application of thermocouples demands that you choose a shape, size and material to match the process. Controls expert Arthur Holland looks at your choices, in ascending order of size and mass, with corresponding increases in robustness and response time.

Bigger Isn't Necessarily Better
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Maybe it's the Fireplace Mentality. Not warm enough? Make the fire bigger. That's fine for relatively low temperature processes, says combustion expert Dick Bennett, but when you get to extremely high temperatures, you need a hotter flame. Otherwise, you can build a fire big enough to burn the place down, and the product will still be standing, unchanged, amid the ashes.

Ramp/Soak Process Controllers
CN7500 Series is encased in a 1/32 DIN enclosure with a 4-digit LED display for local indication of process value and setpoint. Control methods of the ramp/soak controllers include on/off, PID, autotune and manual tune. PID control is supported with 64 temperature-and-time (ramp/soak) control actions. Dual-loop output control allows simultaneous heating and cooling, and the second output can be configured as an alarm mode using one of the 13 built-in alarm functions.

Omega Engineering Inc.
(203) 359-1660

Oil/Gas Shutoff Valves
Valves and valve assemblies for liquid and gas shutoff provide protection for fuel-burning equipment. Approved to FM Class 7400, 7420 and 7422, the shutoff assemblies have a spring-return automated ball valve; explosionproof limit switch and solenoid pilot valve; quarter-turn rack-and-pinion actuator design; valve seating and proprietary stem-seal system. Configurable to a range of shutoff requirements for build-to-order flexibility, the valves are available in three-piece or flanged models, 316 stainless or WCB trim and 0.25 to 6" sizes.

A-T Controls Inc.
(513) 530-5175

Centralized Filter Systems
Providing up to 10 years of filter life with 99.5 percent or higher efficiencies at capturing mist emissions, the mist collector handles effluent from multiple operations, even plant-wide, and treats the stream at a singlelocation. Captured liquids and particulates can be collected for disposal or reprocessing. The horizontal design with side-door access to filters eliminates the need for overhead clearance, simplifying indoor installation. Standard units are available in 18 sizes providing 2,400 to 36,000 acfm capacity.

Ceco Environmental
(800) 220-8021

RTDs
Nickel thin-film RTDs provide a large change resistance in response to temperature changes. Available with resistance values of 100, 120, 500 and 1,000 Ω, nickel thin-film temperature sensors are used in applications such as temperature sensing, energy-management systems and bearing temperature measurement. Available temperature coefficients include 6180 ppm (DIN 43760) and 6720 ppm (ANSI).

DWM & Associates Inc.
(732) 940-4400

Electrically Conductive Adhesive
Aremco-Bond 556 is a two-part, conductive adhesive formulated using high purity silver flake. The system exhibits a volume resistivity of 0.0052 Ω-cm at room temperature and a thermal conductivity of 6.50 BTU-in/hr-ft²-°F. The tensile shear strength is 2,500 psi. It mixes in a 1-to-1 ratio by weight or volume and sets at room temperature in 24 hr. Alternately, it can be heat cured in 4 hr at 170°F (77°C) or 2 hr at 210°F (99°C).

Aremco Products Inc.
(845) 268-0039

Check Valve
Tank overflow assembly protects against infiltration and human tampering. Installed inside the overflow pipeline and hidden from view, the Tideflex valve allows the overflow to drain freely while protecting against airborne pathogens. The assembly comes ready to weld into the overflow pipe and consists of an oversized valve to minimize headloss, reducers and spool piece. Assemblies are available for overflow pipe sizes from 6 through 16".

Tideflex Technologies, Division of Red Valve Co. Inc.
(412) 279-0044