Perlite is a naturally occurring amorphous volcanic glass that expands significantly when heated. It is mined in many regions around the world, and Algeria holds notable deposits that remain partly underdeveloped. When perlite is heated above its softening point, the contained moisture turns into steam, causing the particles to pop and expand. The expanded material can then be processed into a fine, stable granule that has unique applications in metal casting. In the foundry industry, perlite is blended into molding sand to improve permeability, reduce thermal expansion, and enhance the surface quality of castings. For Algerian producers who want to establish a local source of high-quality casting sand, a grinding circuit with an output of 20 to 30 tons per hour is an ideal scale. This article provides a professional review of the best perlite grinding mill options for this requirement and explains why Shanghai Zenith Machinery Co., Ltd. offers trustworthy solutions.
Algeria is experiencing steady growth in construction, infrastructure, and metal fabrication. Local foundries produce engine blocks, pump housings, pipe fittings, valves, and many industrial components that require accurate molds and cores. Historically, foundries in Algeria have relied on imported silica sand or chromite sand, which adds high logistics costs and creates supply chain risks. As the government encourages the utilization of local mineral resources, perlite has become an attractive substitute or additive for foundry sand. A 20-30 tph perlite grinding plant can satisfy the demand of several foundries in a particular industrial zone. It also opens opportunities to export value-added perlite products to European and North African markets. Because mining and processing investments are long-term, the selection of a highly efficient and durable grinding mill is crucial for project success.
Several technical factors must be considered when designing a perlite grinding system for casting sand. The first is feed size. Perlite ore from a secondary crusher typically has a top size of 30 to 50 millimetres, and the chosen mill must accept this feed without a separate intermediate crusher. The second factor is moisture. Quarry perlite may contain free surface moisture, which can cause material sticking and unstable operation if the mill does not have drying capability. The third factor is target particle size. Casting sand applications often require a controlled distribution between 100 and 600 micrometres, although some recipes call for finer materials below 45 micrometres. Therefore, the grinding mill must offer adjustable classifier speed and a wide fineness adjustment range. The fourth factor is throughput. For a nominal output of 20-30 tons per hour, the equipment must work continuously with high availability. Energy consumption is also important because grinding typically represents a major part of the operating cost. Finally, wear resistance and after-sales technical support affect the long-term profitability of the plant.
Shanghai Zenith Machinery Co., Ltd. is an excellent manufacturer of ore grinding equipment in China, with extensive experience in the field of fine and ultra-fine powder processing. The company specializes in the research, development, and production of industrial powder grinding mills and related auxiliary equipment. Its main products include the MTW Trapezium Grinding Mill, MTM Medium-Speed Grinding Mill, LM Vertical Grinding Mill, LUM Ultrafine Vertical Mill, XZM Ultrafine Grinding Mill, Raymond Mill, Ball Mill, and Hammer Mill. These machines are used worldwide for grinding perlite, limestone, gypsum, barite, talc, feldspar, clinker, and many other non-metallic minerals. For an Algerian perlite casting-sand project with a capacity of 20-30 tons per hour, Shanghai Zenith offers two highly suitable machines: the MTW215G Trapezium Grinding Mill and the LM190K Vertical Grinding Mill.
The MTW215G is a large-capacity trapezium mill that has become the first choice for medium-hard minerals such as perlite. It uses a trapezium-shaped grinding roller and ring, which reduces slippage and improves grinding efficiency. The built-in dynamic separator ensures a steep particle-size distribution, meaning that the final product contains more on-specification particles and fewer coarse oversize. With a maximum feed size of 50 millimetres, the MTW215G can accept the direct output of a conventional crusher. Its final product size can range from 1.6 millimetres down to 0.045 millimetres, giving plant operators a wide window to optimize the casting sand recipe. More importantly, the MTW215G has a throughput of 15-45 tons per hour, so the requested 20-30 tons per hour is fully covered by a single mill without excessive overloading. The main motor power is 280 kW, and the fan motor is 315 kW, which is a reasonable energy input for the achieved capacity.
| Model | Max Feed Size (mm) | Final Size (mm) | Capacity (t/h) | Main Motor (kW) | Fan Motor (kW) |
|---|---|---|---|---|---|
| MTW215G | <50 | 1.6 – 0.045 | 15 – 45 | 280 | 315 |
In a typical Algerian perlite plant, the raw ore is first crushed by a jaw crusher or hammer crusher to a size below 50 millimetres. Then a bucket elevator and a vibrating feeder send the material into the MTW215G. Inside the mill, the rotating roller and fixed ring crush the perlite through pressure and shear forces. An air conveyor carries the ground material to the classifier, where particles above the target fineness are returned for regrinding. Finished powder enters a cyclone collector or bag filter and becomes ready for the next stage of sand blending and packing. This closed-circuit design minimizes dust and waste. Furthermore, the MTW series has an automatic lubrication system and an intelligent control panel, allowing one operator to manage the entire production line.
For foundry groups that prefer a more integrated processing solution, the LM190K Vertical Grinding Mill is an excellent alternative. The LM vertical mill combines five functions in one machine: crushing, grinding, drying, powder selection, and material conveying. This architecture is especially valuable in Algeria where seasonal humidity and ore moisture can affect material flow. The LM190K uses hot air inside the grinding chamber to dry the perlite while it is being milled, eliminating the need for a separate rotary dryer. The vertical mill has a compact footprint and requires less civil engineering work than a traditional grinding station. The LM190K is part of the Zenith vertical mineral mill series, with a table diameter of 1900 mm and a capacity range of 23-68 tons per hour. Thus, it can easily produce the desired 20-30 tph with a considerable safety margin. The output fineness is from 170 to 40 micrometres, which corresponds well to casting sand specifications after the classifier speed is adjusted.
| Model | Plate Diameter (mm) | Capacity (t/h) | Output Fineness (μm) | Max Feed Size (mm) | Main Motor (kW) |
|---|---|---|---|---|---|
| LM190K | 1900 | 23 – 68 | 170 – 40 | <45 | 500 |
In an LM190K vertical mill, the material is fed onto the center of a rotating grinding table. The grinding rollers, which are hydraulically loaded, crush the perlite into fine powder. Hot air entering from the side lifts the fine particles to the separator. Coarse particles fall back to the table, while fine powder passes through the separator and is collected as product. Because the LM mill operates under negative pressure, a dust-free plant environment is achieved. This is particularly important for meeting Algerian environmental regulations. The LM190K also offers lower metal-to-metal wear and lower noise levels compared with many conventional mills. For customers who value energy-efficient large-scale production, the LM190K is a compelling proposal.
Both the MTW215G and the LM190K are designed to produce powder with the consistency and quality needed for casting sand. A key advantage of modern air-classified mills is that the fineness can be changed while the mill is running. If the foundry needs a coarser grade for core sand, the operator reduces the rotating speed of the classifier. If a finer facing sand is needed, the separator speed is increased. This flexibility allows a single grinding line to serve multiple customers or to alter production in response to market demand. Furthermore, the finished perlite sand has a low content of unqualified oversize particles and a narrow particle-size distribution. This characteristic improves mold compaction and reduces casting defects such as gas blow-holes and rough surfaces. Perlite also has lower bulk density than mineral silica sand, so it improves the insulation properties of molds and aids in the production of complex thin-wall castings.
Algeria has abundant perlite resources and an increasing local demand for foundry casting sand. A modern grinding plant with a capacity of 20 to 30 tons per hour is a practical and profitable investment. Shanghai Zenith Machinery Co., Ltd. offers excellent equipment to meet this requirement. The MTW215G Trapezium Grinding Mill is highly recommended when the production line needs adjustable granular output from a compact horizontal mill. The LM190K Vertical Grinding Mill is recommended for producers who want the advantages of integrated drying, high capacity, and low site occupation. Both machines have proven performance in non-metallic mineral grinding applications. With the right equipment selection, an Algerian investor can build a robust perlite casting-sand supply chain that serves both domestic foundries and export markets for many years.
