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Features
·
Guaranteed Longest Lasting
Sensors Available with performance guarantee *
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Sensors are compatible with most
existing pH/ORP Meters, Transmitters & Analyzers **
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Application Specific Engineering
results in optimum Lifetime & Performance ***
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Integrated Temperature
Compensation, Preamplifiers & Solution Ground Elements
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Solid State Reference System offers superior resistance to Fouling
& Dehydration
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Applications such as Acid/Fluoride,
Hi-Temp, Saturated Sodium and Sulfide Resistant are available as standard
options
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Custom Applications are available,
often at no additional charge
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Most Installation Styles are
Supported Including: Immersion, Twist Lock, Valve Retractable
& Sanitary
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Available in a wide range of plastics,
from cost effective CPVC to thermally & chemically resilient ULTEM®
and PEEK thermoplastic
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High Pressure Applications up to
100 psi for Valve Retractable & 150 psi for Inline Installations can be
supported for continuous use
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Operating Temperatures from -30
to +150 ºC (-22 to +302 ºF) can be supported
for continuous use
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Case Study No. 9 – pH
Control in Nickel Mining
High Temperature Agitated
Slurry Nickel Ore Mixtures & Solvent Extractions (SX)
Agitated heavy slurry mixtures
are endured by the sensor by use of a strong break resistant thick-wall pH
glass element (nearly unbreakable in most mining slurries)
Build up on reference element is
minimized by solid state reference system, which also allows for aggressive
chemical and mechanical cleaning
Retrofit sensor can connect to
almost any existing pH Transmitter
Advanced waterproofing assembly
allows for continuous submersible installation with little or no solution
intrusion onto cable from back of probe
Unique sealing technology that
is custom built and engineered for mining applications allows for continuous
and aggressive dissolved ammonia gas exposure
Unique organic solvent &
hydrocarbon resistant reference systems and sealing technology allow for
continuous submersed sensor use with little degradation
The Problems
A
nickel mining company wanted to perform pH measurement for sulfide removal by
ammonia injection (leaching) and solvent extraction (SX) portions of their nickel
extraction operations. The high temperature, heavy agitated slurry mixtures
with the presence of dissolved hydrogen sulfide and ammonia gas is quite
similar to that which is described in far greater detail in ASTI’s case
study # 5 problem section. The solvent extraction process utilizes significant
amounts of kerosene, other hydrocarbons and solvents. These extraction
agents in combination with the complex slurry ore mixture present a corrosive
and aggressive process media for measurement. Previously used sensors
required frequent cleaning and recalibration due to organic coating on the
sensors. The need for frequent maintenance accelerated the previously used
sensor’s demise because the frequent removal from the process resulted in
performance degradation due to repeated temperature cycling.
The Solutions
The solution to the
leaching application is similar to that described in ASTI’s case study # 5
solution section, except that the higher process temperatures and heavier
slurry mixture necessitated the use of a thicker walled twist-lock style body
from a PEEK material of construction (see further details in pH sensor used
for leaching on next page of case study). In addition, a more elaborate
cable isolation was required of the waterproofing assembly (Style “B” shown
below) due to the deeper submersion installation. The solution to measuring
pH in solvent extraction mining processes was the combination of an organic
solvent, acid, sulfide and dissolved gas resistant solid state reference
system and thick wall, acid, organic and dissolved gas resistant engineered
pH element. The proper temperature compensation and preamplifier electronics
were integrated into the sensor to allow the retrofit pH sensor to install
directly onto the existing explosion proof Rosemount pH transmitter. The
maintenance requirements and lifetime of the sensor exceeded the previously
used models over three fold, saving operator time and reducing sensor
consumption. Hydrocarbon resistant waterproofing style “E” was required to
ready the sensor for submersible service.
The pH Sensor Used in
Leaching:
Model: PNCTJHRGR 8141/8441/8641-3081-30 pH Sensor - with
Waterproofing Option “B”
Description: 1” MNPT Twist Lock (with Tines) PEEK Bodied High
Temperature, Sulfide, Dissolved Gas and Hysteresis Resistant pH Sensor with Triple
Junction reference system; Integrated 100 Ohm Platinum Temperature Element;
30 feet cable to connect directly to Rosemount 3081 pH Analyzer/Transmitter –
with Waterproofing Option “B” (Shown Below)
The pH Sensor Used in
Solvent Extraction (SX):
Model: PNCLTS 8431/8631-2081-25 pH Sensor - with
Waterproofing Option “E”
Description: 1” MNPT Twist Lock (with Tines) PEEK Bodied High
Temperature, Sulfide, Dissolved Gas, Solvent and Organic Media and Hysteresis
Resistant pH Sensor with Triple Junction reference system; Integrated 100 Ohm
Platinum Temperature Element; 30 feet cable to connect directly to Rosemount
3081 pH Analyzer/Transmitter – with Waterproofing Option “E” Waterproofing Engineering
for Solvent Extraction SX Environments (Shown Below)
Choosing the Correct pH/ORP
Sensor
1.
Choose a sensor body type that
suits the physical parameters of the
installation (refer to the Configurations
Portion of pH/ORP and Ion Selective webpages).
2. Choose
a sensor that suits the process application, temperature,
chemistry, and physical
parameters of the installation (refer to Sensor Selection Guides
and call factory or local sales agent for support)
3. Choose a sensor housing material that is compatible
with the process chemistry, temperature & pressure (refer
to Chemical Resistance Charts as posted under the Technical
Documents portion of the website).
4.
Select suitable temperature compensation element, solution
ground & integrated preamplifier based upon the mating pH/ORP Instrument (refer to Electrochemical Instrumentation
Page & ask for factory support).
5.
Specify the required
cable length based
upon installation
location (refer
to Part Numbering Guide).
*
Subject to application qualification and review by an approved ASTI sales
agent and/or factory. Performance guarantee is posted on the ASTI online
application questionnaire page.
**
See list of supported pH/ORP/ISE Instruments webpages as posted on the ASTI website.
***
Completion of Application Questionnaire form is required. Other restrictions
may apply.
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