Why McLanahan Log Washers
While there are many things that set the McLanahan Log Washer apart in the market, when you work with McLanahan, you are working with the company that perfected the Log Washer. In 1891, Samuel Calvin McLanahan was granted a patent for an ore washing, twin steel shaft machine that is today’s Log Washer. Just as when Samuel Calvin McLanahan originally engineered them, producers can be sure that McLanahan Log Washers today are designed with safety and simplicity of operation in mind, and they are backed by McLanahan's process knowledge to ensure their profitable operation.
McLanahan offers Log Washers with shafts up to 10.6m (35') in length. The length of the Log Washer directly affects the retention time of the material being washed. The longer the washer box, the higher the retention time. There are also several diameters of shaft available. In general, the 36” and 38” diameter Mudmaster units can accept a feed material up to 4” cubed, while the 46” diameter Super Mudmaster units can accept a feed material up to 6” cubed.
McLanahan Log Washers come standard with adjustable weirs at the overflow openings that permit the change in water depth, and can in turn affect the quality of the washed products. All units are equipped with a spray bar for rinsing material prior to discharge. McLanahan recommends that a rinsing screen be used after a Log Washer to provide a final wash. As an option, McLanahan supplies cleanout grates at the bottom of the Log Washer to aid in cleaning the unit of material should maintenance or seasonal shutdowns occur.
All McLanahan Log Washers employ a V-belt driven, single-input, dual-output gear reducer that can be uncoupled from the log shafts and frame for maintenance. Heavy-duty washer boxes are diagonally reinforced on the bottom and vertically along the sides to provide years of maintenance-free use. Standard drive guards and optional top covers are available for personnel protection.
How Log Washers Work
Log Washers remove clays and other deleterious materials by material-on-material inter-particle scrubbing, as well as the interaction with the paddle shafts and water. Clay contaminated hard rock and ore is subjected to a more aggressive washing action than any other type of machine available. Intermeshing paddle shafts scrub and convey the material over the machine length to the discharge, while dissolved clay and mud contaminates overflow a weir in a water slurry when a Log Washer is installed at a proper slope.
Log Washers sit at a slope of zero to 14 degrees depending on the severity of the washing action required. As the percentage of deleterious material increases, the slope must be raised to increase retention time. Under certain conditions, lower slope can increase the capacity while decreasing usage power and wear. It is recommended to establish the lowest operating slope while maintaining a clean product to take advantage of low usage power consumption and parts wear.
As deleterious material is liberated, clean material moves forward between the shafts and discharges out the bottom of the box after a final rinse by a spray bar. Deleterious clays and silts are dissolved and absorbed into the water and carried over a weir on either side of the box. In high capacity applications, an optional rising current system helps lift waste fractions to the top of the water level and over the weir.
When selecting a Log Washer, the type of feed material must be taken into consideration. The size and shape of the feed material can affect the capacity of a particular size unit. McLanahan will be able to provide a list of capacities and water requirements based on your feed material.
It is recommended that the sand-sized fraction is removed prior to the Log Washer since finer material tends to cushion the washing action. The sand fraction should only be fed to the Log Washer when severe washing of fines is required. When processing fines, it is necessary to capture the overflow of the unit to save them for further processing.
Popular Applications for Log Washers
Log Washers are widely used for washing materials, including hard rock ore, gravel, limestone and phosphate, that have tough, plastic sticky clay contaminants. Feeds having up to 15% clays can be removed in a single unit. The largest feed size can be up to 150mm or 6”. While the machine has a spray bar near the discharge for an additional rinsing in most instances, it is recommended that the rock or ore be further washed and, as required, separated on a washing/vibrating screen.
Benefits of McLanahan Log Washers
- Log shafts are fabricated from extra-heavy, one-piece steel pipe and flanged at both ends to facilitate maintenance
- Bolt-on, abrasion-resistant paddles are affixed to a twin shaft design to ensure an aggressive washing action that breaks down even the toughest clays
- Twin-Seal Pak submerged rear bearing assemblies incorporate Caterpillar Duo-Cone® seals that keep water and even the smallest particles from reaching the bearings
- McL5X paddles are made of specially developed fine grain steel for optimum hardness and maximum abrasion resistance
- Cleanout gates are available and positioned at the underside of the washer box
- Spiral or straight row paddle configuration on the shafts are available
- Capacities of up to 500 tph in a single X-Treme Super Mudmaster Log Washer
Frequently Asked Questions
What different sizes and models of Log Washer does McLanahan offer?
- 91.4cm (36") diameter paddle swing — available in 7.6m (25′) and 9.1m (30′) lengths
- 96.5cm (38″) diameter paddle swing — available in 9.1m (30′) and 10.6m (35′) lengths
- 116.8cm (46″) diameter paddle swings — available in 9.1m (30′) and 10.6m (35′) lengths
How much does it cost?
Contact McLanahan or your nearest authorised local dealer not only for pricing, but for discussions on suitability and use for your application.
What are some key application questions I should have answers for regarding my problem?
You should know the type of clay/silt contamination that needs removed, the ore/rock feed size, the tons per hour feed solids capacity, and the process flow and equipment location of the required washer in your processing plant.
What other technologies should I consider?
What are some key equipment options to consider?
Consider V-belt drive guards and top protective safety covers.