Oli Vibrators in partnership with Vibroflow has delivered key equipment for an advanced glass recycling plant.
Recycling glass saves energy, cuts down on the need for raw materials, and loses no quality when turned into a new product.
However, when it comes to co-mingled waste streams, it can become difficult to handle. Broken glass can be hazardous to workers and machinery, it can be hard to sort, doesn’t compress in transport, and can contaminate other recycling streams.
As part of its commitment to improve Victoria’s recycling system, waste services company Citywide has unveiled a new glass recycling plant capable of cleaning glass from co-mingled bins and highly contaminated material that can’t be processed by other plants.
In addition to diversifying waste from landfill, the plant will produce up to 400 tonnes of high-value sand replacement products each week, which can be used for everything from cement production and sandblasting to asphalt for roads and pavements. It will also naturally reduce the construction industry’s voracious appetite for virgin sand.
Claire Bright, Citywide’s sustainability manager, said the new plant would be able to recycle “challenging” glass loads that could not be treated by other plants due to their small particle size or contamination with plastics or paper.
“A lot of plants can only process glass particles over a certain size, so they wind up with a lot of material that’s too small to go through their machines,” Bright said.
“Our plant will be able to support these operators in processing their difficult-to-process glass, as well as acting as a demonstration site for multiple other recycling and repurposing solutions.”
Because crushed glass forms a concrete like material when wet, great effort was taken to design a drying system that would reliably remove the moisture from the product.
Wastetech worked alongside vibrator specialists Vibroflow and Oli Vibrators to design several key pieces of equipment to ensure the glass could be recycled.
A vibrating feeder/taper slot screen was designed to be placed at the beginning of the material stream. It withdraws material from the storage hopper, removing oversized impurities.
Anthony Sokolowski, general manager of Vibroflow, said the taper slot system is an innovative way to reduce material blocking in the apertures.
“A large stroke is required to reduce material blocking in the apertures. To achieve this, Vibroflow used two OLI MVE 2100/075 eight pole vibrating motors,” he said.
“These motors operate at 750rpm and allow a greater movement to be achieved compared to six and four pole motors.”
Another key part of the plant is the triple deck screen, which includes a three mm, 1.5mm and 0.4mm aperture screening decks.
The unit is located at the end of the process, where it sizes the final glass product. Different sizes of glass can be used for different products. Smaller particles could be used for glass bead blasting, while larger particles can be used for roads or paint.
“Large strokes are not required for this machine as most of the difficult particles are either crushed or screened out by this stage,” Sokolowski said.
“This machine needs a medium / fast vibration with a low stroke to maximise screening efficiency.
“For this purpose, Vibroflow has used two OLI MVE 3800/1 vibrating motors. These operate at 1000rpm and allow for a good balance between speed and stroke.”
The glass recycling plant is set to play a significant role in Victoria’s container deposit scheme, which is expected to commence in 2023.
Duncan Reid Citywide Operations Executive said the glass plant will become one of many circular economy projects at its West Melbourne site.
“We are in the midst of a generational change right now in how we deal with waste and recycling products,” Reid said.
“We have quite literally reached a tipping point where we are rightly assessing the recyclable value of existing products.
“The circular economy is all about examining every waste product we can possibly divert from landfill and repurposing it in a sustainable way.”