JULY 2017 • E&MJ; 81 www.e-mj.com
PROCESSING SOLUTIONS
than when choosing a service-only vendor.
This approach brings business agility and
increased effi ciency from implementation
through ongoing life-cycle operations.
Customers can take advantage of the lat-
est software with less on-site support and
maintenance skills required. They also
benefi t from a lower cost of entry with the
potential for reduced CAPEX, rapid proj-
ect deployment and lower life-cycle costs.
Installation of FeedAirJet
Sparger Brings Better Metal
Recovery
Eriez Flotation Division recently report-
ed on early results from installation of
its fi rst FeedAirJet on a cleaner column
at Capstone Gold's Cozamin concentra-
tor in Zacatecas, Mexico. Nicknamed by
the commissioning team as the "Cavita-
dor," the FeedAirJet is a simple system
for pre-aerating fl otation feed streams. It
is based on a proprietary confi guration of
Eriez's CavTube, a sparging system that
has been installed on more than 200 col-
umns worldwide.
The CavTube works by inducing hy-
drodynamic cavitation in the feed slurry,
which nucleates fi ne bubbles selectively
on hydrophobic surfaces of the ore. The
FeedAirJet turbo-charges the fl otation
process by starting particle collection be-
fore entering the fl otation vessel.
Results obtained by Capstone report-
edly confi rmed this. Cozamin's plant
manager, Rafael Regino, said "The recov-
ery of copper and silver were consistently
increased an average of 0.8% and 3%,
respectively, when the FeedAirJet was
added. Another impressive result was that
recovery increased in all measured size
classes." He added that, based on these
results, another FeedAirJet had been ap-
proved in April for a zinc column.
According to Eriez's representative
Oscar Lopez, "The FeedAirJet is a low
risk, low capital way to improve fl otation
performance, and can be readily installed
in existing plants. Five other plants in
Mexico are evaluating this technology by
installing the 'Cavitador' to increase re-
covery and reduce the re-circulating load
in the fl otation cleaner stages. We believe
this technology should also improve the
performance of forced air and aspirated
mechanical cells."
Weighing the Options:
Choosing the Right Belt
Scale System
Few, if any, industries handle more heavy
material in bulk than mining, whether
measured on an an hourly, daily, weekly
or annual basis. Much of this material
must be weighed and monitored before or
as it is fed to plants for processing. Belt
conveyer scales are an important part of
a mining operation's bulk material han-
dling system. A belt scale system allows
an operation to monitor production output
and inventory, or regulate product load-
out, while providing vital information for
the effective management and effi cient
operation of the business. Picking the
right belt scale system to meet the spe-
cifi c needs of an operation is essential,
but what are the most important factors
and options to consider? Thermo Fisher
Scientifi c recently addressed the problem
in a blog post.
Starting at the most elementary level,
the post explains that a belt scale system
consists of three major elements: the
weighing carriage with load cell(s) mea-
sures the weight of material on the belt,
the belt speed sensor and electronic in-
tegrator joins the output signals from the
scale load cell(s) and speed sensor to ar-
rive at a rate of material fl ow and the total
material passed over the scale.
The weighing assembly consists of ei-
ther one or two modules, depending on
conveyor width. The modules support the
weigh idler and measure the weight of
material on the belt. The speed sensor is
mechanically connected to the conveyor's
tail pulley and generates a stream of puls-
es. Each pulse represents a unit of belt
travel. The frequency of the pulse stream
is proportional to belt speed. The elec-
tronics integrate the output signals from
the scale module(s) and speed sensor to
arrive at a rate of material fl ow and the
total material passed over the scale.
Some belt scale systems provide basic
rate information and totalization func-
tions in processes involving non-critical or
lower value materials with an accuracy of
±1%. Other belt scale systems can moni-
tor the feed processes with an accuracy of
±0.5%, or with better-than-normal accura-
cy of ±0.25%. Most belt conveyor scales
are capable of providing reliable results
within ±½% of their full-scale rating.
There are other options to consid-
er when considering belt scale sys-
tems: idlers, idler spacing, load cells,
belt widths, belt loading amounts and
even considerations for the type of ap-
plication. Some systems are better for
high-value materials while others are
more cost-effective for non-critical or
lower value materials.
To help users decide which belt scale
system is best for their mining operation,
the company has outlined the options in
a belt scale system selection guide, avail-
able online at www.thermofi sher.com/us/
en/home/industrial/cement-coal-miner-
als/bulk-weighing-monitoring-sampling/
belt-scale-selection-guide.html.
The CavTube sparger has been installed on more than 200 columns worldwide. A version of the system operating at
a Mexican hard rock mine has resulted in improved fl otation performance, according to the manufacturer.