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Application Info
Minera Mantos de Oro (Chile) is thelargest gold mine producer in
South
America. Within the modernizationprogram to increase the
efficiency of operation, Endress+Hauser waschosen as a proven
supplier foranalytical instrumentation.
Customer requirementsThe cyanide leaching process is one of the
most important production stepsat any gold mining factory. Gold,
asa noble metal, can only be dissolvedin limited solvents. For
industrialpurposes the diluted solution of NaCN and CaO is used. To
achievemaximum gold extraction and to make
COS61 reduces costs by 30% in gold mining Cyanide leaching
process under complete control with optical sensor
the reaction complete, compressed airmust be introduced into the
crushedore (pulp) and constantly controlled.The customer needs a
solution forthe reliable measurement of dissolvedoxygen, pH and
ORP.
SolutionConsidering the challenging operating conditions - high
pulp viscosity together with a high concentrationof abrasive
particles, the following solution was offered: optical sensorOxymax
COS61 for dissolved oxygenmeasurement with the LiquisysCOM253
transmitter.
The leading zinc manufacturer inRussia, JSC Chelyabinsky zinkovy
zavod, produces 200 000 tons per
year. The company, located in thesouthern part of the Ural
Mountains,recently modernized its leaching site.
Customer requirements The acidic leaching stage is one of the
most critical processes in the zincproduction chain. The measuring
point has challenging operating conditions -abrasive particles,
non-properly crushedore sometimes measures more than50 mm in
diameter, high temperatureand low pH values. As a result,
thecustomer spends a lot of resourceson maintenance and
consumables,and cannot ensure reliable processcontrol. The task for
Endress+Hauser
was clear - keep the process under
control and reduce the costs.
Tophit hits the target!Reliable pH control in the zinc leaching
processSolution Considering all the challenges, SCRussia offered
the following uniquesolution: Tophit CPS491D, the virtually
unbreakable and robust non-glasspH electrode with open
aperturecombined with the Chemocleancleaning system. Considering
thetechnological requirements, sulfuricacid with a concentration of
5% waschosen as the cleaning agent. Thecleaning frequency was
defined onceper 2 hours with a cleaning durationof 3 minutes. To
control the levelof cleaning agent in the canister, alevel meter
was also installed.
Customer benefits The optical technology used in COS61sensors
helps to reduce the overallcost of ownership by about 30%,
which translates to savings of approx.10,000.
The key factors are: Up to 3 - 4 times less
maintenance required Cost savings on consumables
compared to conventionalamperometric sensors
Aleksey Zhidkov / Areamanagement
Customer benefitsThis solution met 100% of thecustomers
expectations: 35% cost savings per year (approx.
12,000) thanks to savings onconsumables because the lifetime of
the Tophit electrode is 5 times longerthan electrodes from the
competition
Cost savings on maintenance costs Reliable process control
Aleksey Zhidkov / Area Management
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Topcal S reduces monthly maintenance by 2,100 hoursTopcal
systems help to decrease magnesium in zinc concentrate. IMN and ZGH
Boleslaw S.A. (Poland) developed a unique method to decrease
magnesium concentration in zinc mineral pulp. Demagnetization takes
place in six reactorsas batch processes and is fully pH
controlled.
Application Info
pH in zinc extraction
Customer requirementsThe installation for manufacturing
low-magnesium zinc concentrate wascompleted in July 2007. The
process iscarried out in five leaching tanks andone neutralization
tank. In two hoursof the batch process, the pH value of the milled
dolomite concentrate iscontrolled in four steps (1.5 - 4.5) by
adding 96% sulfuric acid. Magnesiumsulfate in a liquid form goes
into thesolution and gypsum is removed in theflotation tanks.
SolutionpH is an essential parameter, whichcontrols the whole
process andconsequently influences the quality of the final
product. The operating conditions are rather harsh: highly
concentrated and abrasive mineralpulp, deposit growth on the
electrodeand thick tank walls.
The selected instrumentation: sixTopcal S CPC310 equipped
withOrbisint CPS11D-7BA51 and Cleanfit CPA472D-C1B2E2D3. This
choice
was combined with 3% HCL cleaning after each batch (60 seconds
water, 3seconds HCL, 60 seconds HCL soaking,
60 seconds water) and proved to be theoptimal solution.
Customer benefitsSix Topcal S systems save more than2,100 hours
per month in maintenancecosts thanks to automatic cleaning and
calibration. Above all, the zincconcentrate with a
magnesiumconcentration of < 0.1% (market average is 0.3%)
results in low energy consumption in zinc electrolysis.
Marek Gryniuk / Area Management
