Mainland Machinery Ltd

Dry Flocculant Mixing and Feeding Design Considerations

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This is a guest post by Bill Hancock, President of Zeroday Enterprises

Dry Flocculant Mixing and Feeding Design Considerations

Dry flocculant wetting, dissolving, mixing and solution feeding must be done under very specific controlled conditions that account for the flocculant’s unique physical and chemical characteristics. Failure to ensure proper polymer solution preparation and feeding can result in mix-feed system plugging and erratic operation, process control issues and wasted polymer.

Key flocculant characteristics that must be considered for proper flocculant mixing and use are summarized below:

1)    Flocculant powders are hydroscopic. Storage and dry polymer feeding systems must ensure minimum air contact as the particles will adsorb moisture which initiates flocculant dissolution. Dissolving particles are very sticky and consequently will aggregate into larger pieces and chunks. These larger pieces and chunks dissolve slower and often can plug equipment causing mix system and even process operational disruptions.

2)    Water wetted flocculant particles can aggregate into masses. Since flocculant particles dissolve proportionately to exposed surface area, particle aggregates that have stuck together result in significantly reduced dissolution rate during mixing. If the flocculant aggregates do not fully dissolve within the set system residence time, these partially flocculant masses will pass through the mix system and process unused. And possibly plug equipment. Note: flocculant particles/aggregates will hydrolyze throughout into a clear gel which refract light differently than water, these masses are called ‘fish eyes’ because can predominantly see the light refraction, not the mass itself.

3)    It is very important to initially wet each flocculant particle. The mixing system must be designed in the first step of the mixing process to wet each particle individually and immediately, and subsequently ensure these wetted particles do not aggregate or agglomerate. There are two main mix system flocculant particle wetting categories.

  1. Augering flocculant particles into a funnel with plenty of water flowing in the funnel followed by some motive dispersive force to ensure any particles that might stick together will be pulled apart.
  2. The flocculant particles are air blown from an auger into a large diameter hose to the top of the mix tank where cascading water inside a tube wets the particles which enters the mix tank and impeller.

4)    Flocculant dissolution time variable. Flocculants dissolve at different rates, primarily dependent on the following factors.

  1. Type of polymer charge
  2. Flocculant charge level
  3. Water temperature and chemistry

Required mix times can range from 30-90 minutes are designed into a mix system.

5)    Flocculant solutions are viscous. Dissolved long chain flocculants introduce solution drag that is expressed as viscosity. The amount of viscosity is dependent on the flocculant charge, charge level, temperature, concentration and molecule chain length. More viscous solutions require more mixing power. To ensure the flocculant molecule chains are not broken, balancing the amount of power in mixing and the type of mixing are crucial for minimizing dissolved flocculant chain damage.

6)    Low shear pumps must be used for flocculant solution transfer and feeding. The two more predominate low shear pump types are progressing and diaphragm. More specifically, examples of pumps that are acceptable include progressive cavity, peristaltic, gear, lobe and air operated diaphragm.

7)    Flocculant solutions typically provide best performance at ≤ 0.1% concentrations. To optimize flocculant mixing system sizing, flocculant solutions are often designed to be mixed to 0.25-0.50% maximum concentration. Once dissolved, the flocculants will dilute readily with teed in water down stream of the flocculant feed pump to obtain the final target 0.1% concentration.

Flocculant mixing and feeding is not highly complex. But the unique flocculant characteristics accounted and designed into a mixing-feeding system to ensure optimum preparation and minimized consumption.

Bill Hancock is an internationally recognized expert in mineral processing technologies, technical marketing management and water treatment. Hancock founded and owns Zeroday Enterprises which supplies chemical mix-feed systems, LTM conductive slurry level monitoring probes, peristaltic hose and tube pumps, mixers and flocculant and coagulant chemicals. He also founded Argo Consulting—a technical and technical marketing consulting practice focused on providing mineral processing, water treatment and technical marketing consulting services to the mining industry.

Mainland Machinery Ltd

Thickeners: How they Operate

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This is a guest post by Bill Hancock, President of Zeroday Enterprises

Thickeners: How they Operate

The most common solids-liquid (S/L) unit operation is thickening. A wide variety of thickeners are used including conventional, deep well, paste, high rate and clarifiers which is a thickener subclass used for removing solids from turbid or very low % solids waters. Thickeners are mechanically continuous process equipment which operates on a particle/floccule sedimentation principle where in simplest terms the solids settle to the bottom of the thickener tank and the water overflows the tank.

Essential elements common to thickeners include:

a)  Feedwell: where the slurry or water is introduced into the thickener which confines the kinetic energy of the incoming waters to minimize overall tank turbulence as well as directing the flow downward into the thickener

b)  Rake mechanism: or similar device that pulls the settled solids/mud to the center of the tank; as the rakes travel through the mud, this plays an additional important role in disturbing the mud and releasing additional water retained by the settled mud

c)  Under flow pump: which can be of several types including peristaltic, centrifugal, diaphragm and progressive cavity.

Thickeners are designed to operate continuously with slurry/water consistently flowing into the centerwell with thickener underflow pumping balanced to maintain a mud bed in the thickener. Key to thickener operational efficiency is the solids must be able to settle 2-4 times faster than the nominal water up flow rate. High feed solids recoveries reporting to the bottom of the thickener ensures high solids recovery and high overflow clarity levels.

Modern thickeners are designed based on use of highly effective synthetic (polyacrylamide) flocculants, ensuring high solids capture and adequate settling rates. Coagulants are sometimes also used when fine particle recovery is a challenge with flocculants alone. Fine particle recovery is needed to maximize thickener overflow clarity, minimize sands-slime separation in the bed which causes torque issues and to ensure bed solids flowability. Additionally coagulants can have positive downstream operational benefits such as in filters.

Flocculants are typically introduced either to the slurry-water pipe feeding the thickener, to a feed tank before the thickener, to the centerwell or a combination of these addition points. Where flocculant is optimally dosed is typically determined by plant evaluation and varies from operation to operation and is influenced by solids substrate, particle sizes and system specific factors. If coagulants are used, typically these are dosed upsteam of the flocculant addition point; however, in mineral concentrates, most often the best response is dosing coagulant after the flocculant.

Settled solids at the bottom of the thickener is called ‘mud’. The goal is to maximize the % solids in the underflow to recover as much water as possible for reuse. Primary means for controlling % solids is by mud depth and flocculant dosage. Deeper mud depths increase % solids because mud weight will cause more water to be released. Higher flocculant dosages, within a normal dosage rate range, will result in higher % solids. The % solids is typically limited by the thickener’s ability to transfer mud from the thickener and pumping the underflow because viscosity and slurry density increases dramatically with increasing % solids.

The simple animation below that shows only flocculant addition (not coagulant) illustrates these thickener operational principles.

 

Bill Hancock is an internationally recognized expert in mineral processing technologies, technical marketing management and water treatment. Hancock founded and owns Zeroday Enterprises which supplies chemical mix-feed systems, LTM conductive slurry level monitoring probes, peristaltic hose and tube pumps, mixers and flocculant and coagulant chemicals. He also founded Argo Consulting—a technical and technical marketing consulting practice focused on providing mineral processing, water treatment and technical marketing consulting services to the mining industry.

Mainland Machinery Ltd

Exciting New Partnership with Zeroday Enterprises

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Announcing New Partnership with Zeroday Enterprises

Mainland Machinery Ltd and Zeroday Enterprises LLC are pleased to announce a partnership to advance Zeroday’s chemical mixing and feeding technology. As of August 9, 2016 Mainland has been named the exclusive distributor and manufacturer of Zeroday’s Z ChemGear product line of flocculant, chemical and regeant mixing and feeding systems!

Mainland and Zeroday Partnership

Zeroday is an industry technology leader in process, water and wastewater treatment, and brings extensive chemical knowledge and experience used in designing quality, effective and robust chemical mixing-feeding systems. Mainland has over 45 years of value added manufacturing and engineering experience with involvement in diverse industries such as mining, oil & gas, municipal infrastructure, industrial agriculture and ports & terminals. The mutually supportive skills and core capabilities of each partner will enhance business competitiveness, capabilities and product line strength.

Mainland and Zeroday Partnership

With locations in Wilsonville, Oregon and Abbotsford, B.C., we will continue to sell and support systems globally through EPCM, third party vendors and directly to customers. Canadian sourcing is expected to make the mix-feed systems much more competitive.

Zeroday’s Principal, Bill Hancock, is internationally recognized for his expertise in mineral processing technology and water treatment, and holds patents in flocculation and flotation applications. Bill will be involved in product line, sales and technical support, as well as independently promoting product line sales.

Mainland is pleased to be working alongside Zeroday Enterprises to produce innovative and cutting edge technologies! And Zeroday is excited about partnering with Mainland who will provide greater engineering and fabrication resources and expertise.

To inquire about products to meet your floc system neeeds, please contact sales@mainlandmachinery.com

To learn more about Zeroday, see their website

Mainland Machinery Ltd

New Maintenance Inspection Program

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Maintenance Inspection Program
Mainland Machinery is happy to introduce our new Maintenance Inspection Program.

With over 45 years in Industrial Manufacturing and Maintenance, and knowledgeable staff that are attentive to detail, we are well versed in what is needed to keep facilities operating at their best.

Built with the primary goal of providing our customers an overall assessment of the condition of their facility, we are able to provide insight and suggestions on preventative, corrective, perfective and adaptive maintenance.

Contact us now to schedule your Plant Maintenance Visit at an introductory rate

Equipment Installation Services
With services ranging from Installation to Commissioning and Decommissioning, we are capable of taking on mechanical installations or special installation projects. Our field personnel have a wide range of industry experience and are comfortable working in any environment.

Learn more about our Equipment Installation. Commissioning and Decommissioning services
Mainland Machinery Ltd

HELP US BREAK IN OUR NEW BRAKE PRESS – INTRODUCTORY RATES!

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HELP US BREAK IN OUR NEW BRAKE PRESS – INTRODUCTORY RATES!

Mainland Machinery’s Machining Center is fully operational and capable of meeting your heavy plate forming and project needs.

brake press

Our recently opened third facility located in Aldergrove, BC features our new Accurpress Model 7 1500 16 Brake press with ETS3000 Control System.

brake press

Mainland Machinery’s state of the art Accurpress Brake Press is now available for your heavy plate forming needs. We are pleased to announce that we are currently processing orders for its use at introductory rates.

Visit our website for more information and to submit a request form

brake press

Product Capacity

  • 1500 ton
  • 16′ Bed with increased opening of 4″
  • 575 Volt motor
  • Series 7 (rocker arm style)
  • Die Holders
    • 12W-2H-16′
  • Bends 1″ plate

bending resized

Visit our website for more information and to submit a request form

 

Mainland Machinery Ltd

Metal Cutting Methods

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Metal CuttingChoosing the Best Cutting Method for Your Metal Project

There are many types of metal and each requires different metal cutting techniques. Because of this, there are a variety of methods available to cut metal materials. The method you choose for your project will depend on the type of metal being used, the level of precision that is required and the intended use of the fabricated part and project.

Hand Tools for Cutting Metal Manually

For smaller cutting jobs, hand tools, including hand shears and hacksaws may be used for cutting metal into the desired shape. This cutting method is best suited for projects using more pliable metals, such as thinner-gauge aluminum. Using hand tools to cut metal is not recommended if the metal must be cut into extremely small pieces because the force needed to cut the metal may simply break it, instead of cutting it as intended.

Chisels can also be used to remove excess metal and to make a shape more precise. Depending upon the job, you may opt to use a cold chisel, with a sharpened edge or a hot chisel, which is heated before being hammered through metal.

Using Machinery to Cut Metal

For larger projects or those that use thicker or more robust metals, manual cutting is not always practical. There are numerous machine-based cutting methods to choose from, based on your metal cutting needs.

  • Grinder – For projects that require the finished part to be extremely smooth, a grinding machine may be your tool of choice. Using a rotating blade or wheel made of an abrasive material; a grinder uses friction to wear down the surface of the metal until it is smooth, similar to sanding wood.
  • Lathe – Using a sharpened cutting tool against a rapidly spinning piece of material, a lathe will cut a piece of metal to its desired shape. This machine is very common in the machining industry because it allows for a higher degree of precision.
  • Punch – This machine uses an extreme amount of pressure to force sharpened blades into or through metal to cut it into the shape desired. The amount of pressure generated by a machine punch is far greater than any human worker could produce, thus this cutting method is suitable for metals that are more robust. Some machine punches are capable of up to 1,000 hits per minute, making this cutting method very productive.
  • Water jet – Using water or water mixed with an abrasive compound, this machine directs an intense and concentrated stream into metal and cuts it. This method is best suited for metals that may be sensitive to extreme heat or temperature changes because it does not use heat in the process.
  • Flame and plasma – This process is similar to a water jet, but instead a flammable gas is pumped through a torch to create an intense hot flame. The flame then cuts the metal by burning and melting it. Flame torches, such as oxyacetylene torches are very efficient for cutting. Plasma cutters are known for their high degree of precision because they burn much hotter.

Greater Precision in a New Method of Metal Cutting

Laser cutting is one of the newest and most exciting methods in cutting technology. These cutters apply an intense beam of light to the metal, heating it past its melting point, and then cut through the metal. A laser cutter is able to concentrate light onto a very small area, which makes this method suitable for projects that require a very high degree of precision. However, this method is slower and more expensive than other methods of metal cutting.

Mainland Machinery Ltd

Robotic Mining Equipment: Are We Ready for Automation?

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mine operator safetyIs The World Ready For a Fully Automated Mine? 

In the last few years, mining operations have taken advantage of robotic mining equipment to perform some of the more dangerous and repetitive tasks the industry requires. However, despite their high costs, is it possible that a fully automated mine is on the horizon?

There are three reasons why it might be.

Safety

Mining is an inherently dangerous industry. After all, it entails using large machines to drill holes in the Earth, pack them with explosives, and blow them up. Even with the most stringent safety protocols in place, the rate of workplace injuries is higher than most other industries.

However, there are other reasons why safety is compromised in the mining industry. Many of the less dangerous tasks are repetitive and mind numbing, a good example being driving haulage trucks. The job consists of driving from point A to point B and back again. Human drivers are susceptible to boredom and attention drift. That lack of attention is what makes a safe, routine task one where two people are killed every year.

In the mines, robotized mining industry equipment can perform the routine and repetitive tasks, in order to save employees for important tasks.

Efficiency

Robotic mining industry equipment doesn’t need the same kind of breaks that people do. To be sure, they are subject to maintenance, but that can often be done on a predictable schedule, which isn’t true of human labor.

It goes beyond that, of course. Automation allows operations to get closer to the text book optimums for load size and frequency while also allowing for shifts in load sizes due to potential short-term fluctuations.

The use of robotics in scouting for locations offers another opportunity for efficiency. While a manned helicopter could cost as much as $2000 per hour to operate, a drone with a camera costs a mere $500 per hour, meaning drones can cover four times as much territory for the same cost in the same time frame.

Productivity

Robotic mining industry equipment can operate in more dangerous locations, perform repetitive tasks with less loss of efficiency, and aren’t subject to the same workplace laws that humans are. But these are only the most obvious ways they are more productive.

Mining is not an industry that can pick and choose where the job gets done. The job goes where the raw materials are, and if there is a sizeable population of experienced miners, it will be more successful. However, if the area is remote, the operation is faced with either shutting down at times because there are not enough able workers to do the job on a full time basis, or bringing in workers from outside the region. Bringing in workers helps to keep the mine open, but comes at a substantial additional cost.

By performing many of the most repetitive and dangerous tasks, robotic mining industry equipment might actually lower the number of human employees necessary for an operation. Where this is not the case, robotic mining industry equipment will allow organizations to shift their workforce to safer jobs that require a less specific skillset.

In addition, automation would eliminate the need for all workers to be on site, which would allow an organization to place its workforce closer to a population center to eliminate or reduce the need to bring in workers from elsewhere.

A fully automated mining operation is not yet a reality, but with an increasing number of mining tasks being automated every day, it’s only a matter of time before a fully automated operation is possible.

 

Mainland Machinery Ltd

Magnetic Separation in the Mining Industry

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mining industryWhy Magnetic Separation Matters for the Mining Industry

One of the greatest challenges facing the mining industry is the separation of unwanted material generated by the extraction process from the valuable material. Mining, whether done through open seam or underground means, creates a huge amount of waste product in the form of worthless or low value minerals and unusable man-made materials. These materials can be extremely difficult to separate from the valuable materials miners are after. Perhaps the most efficient way of separating these materials is through magnetic separation.

What is Magnetic Separation?

Magnetic separation is the process of using magnetic force to remove metallic or ferrous materials from a mixture.

Magnetic separation machines consist of a vibratory feeding mechanism, an upper and lower belt and a magnet. The bulk material is fed through the vibrating mechanism onto the lower belt. At this point, the magnet pulls any material susceptible to magnetic attraction onto the upper belt, effectively separating the unwanted metals from the rest of the bulk.

How Magnetic Separation is Useful

Magnetic separation has been used in the mining industry for more than 100 years, beginning with John Wetherill’s Wetherill Magnetic Separator, which was used in England in the late nineteenth century.

Magnetic separation is most commonly used in the mining industry to separate “tramp ore,” or unwanted waste metals, from the rest of the bulk material. Tramp ore typically consists of the man-made byproducts created by the mining process itself, such as wires from explosive charges, nuts and bolts, nails, broken pieces from hand tools such as jack hammers and drills or tips off of heavy duty extraction buckets.

Magnetic separation machines are usually placed at the beginning of a mine’s materials processing line to remove tramp ore before it can cause harm to “downstream” equipment such as ore crushers and conveyor belts, which can be easily damaged by metal shards or other sharp objects.

Most magnetic extraction systems are designed to be easily retrofitted onto existing production and conveyor systems, so major equipment relocation is unnecessary.

Types of Magnetic Separators

The type of magnetic separator used by a mine depends on what material they are extracting and how much tramp ore is generated by their process. As a result, separators of different magnetic flux, or power, can be used. There are 2 types of magnetic separators; electromagnetic and permanent.

Electromagnetic separators generate a magnetic field by switching power from alternating current to direct current. Electromagnetic separators are useful for removing large pieces of tramp ore from the bulk material. These separators are typically suspended over a conveyor belt and draw the unwanted material upward. Electromagnetic separators are easy to clean as removing the tramp ore that they separate from the bulk is as simple as turning off the power that creates their magnetic field.

Permanent magnets consist of materials that generate their own magnetic field. Though not as powerful as electromagnetic separators, permanent magnets are better at attracting strongly magnetized materials such as nickel, cobalt, iron and some rare earth metals. Some permanent magnets are now being made with rare earth metals that have the ability to attract even stainless steel, which is typically not susceptible to magnetic pull. In order to clean permanent magnets, a stainless steel scraper must be used to remove any metal parts from the magnet’s surface.

 

Mainland Machinery Ltd

The Sheet Metal Stamping Process: How Does it Work?

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sheet metal stamping processHow Does the Sheet Metal Stamping Process Work?

Sheet metal is one of the strongest materials that can still be easily shaped and cut. Plus, sheet metal is recyclable, which drives costs down.

Metal stamping is used to produce parts in many industries. Original Equipment Manufacturers (OEM) most often make use of sheet metal stamping to make their parts where casting would be too expensive. It’s inexpensive and efficient, but it’s likely you don’t really know how it works.

First, the basics.

Some OEMs produce their own stamped sheet metal on site, while others outsource to Tier 1 suppliers. It is these suppliers that build the dies for stamping down the line.

Sheet metal itself is usually made of steel, but stamping can be done with all kinds of metals, including golds and advanced super-alloys.

Basically, sheet metal stamping involves a flat metal sheet, also known as a blank, being pressed between a die and a punch to get the desired shape.

  • Blank – the portion of the sheet metal which is punched through the die
  • Die – defines the outside shape of the part
  • Punch – defines the inside shape of the part
  • Ram – moving component which presses down on the metal with upper die pattern
  • Bolster Plate – stationary lower part of the die
  • Blank Holder – holds the blank for control during stamping

These parts form the press, the ultimate tool of stamping sheet metal.

Of these, the die is probably the most complicated, and are often designed with inserts to produce variations on standard presses. You’ve probably seen dies used to make novelty souvenir coins — dies can be used for all kinds of processes and materials.  They can be small enough to build microelectronics or large enough to cut out sides of busses.

Presses can be built as single stage or progressive blanking tools.

  • Single Stage Press – stamping operations are done before or after the blanking
  • Progressive Blanking Press Tools – stamping is done by the machine prior to blanking, so the complete component is punched out throughout the blanking die.

As blanks are punched out of the sheet metal, the come through the die, which is built with a slight angle so that blanks don’t get stuck inside the die. Accidental hold ups can damage the machine, so it’s important that the stamping and blanking process continues smoothly.

Sheet metal presses are powerful machines. It takes about 71 tonnes of pressure to cut a 10 inch circle out of .125 inch sheet metal. Modern presses range from 10 to 50,000 tonnes of force.

Several people are involved in the stamping process:

  • Machinist – cuts die components to correct dimensions
  • Diemaker – tests die for consistency and assembles stamping tool
  • Maintenance Technician – repairs and maintains stamping dies, correcting any problems.

After stamping, some parts require further work in a process known as deep drawing. In deep drawing, a flat blank is drawn slowly over a forming die to achieve its shape. Next, excess material must be cut from the deep drawn metal. Finally, the metal might need to be bent, flanged