Download SATMAGAN S135 MAGNETIC ANALYZER

SATMAGAN
MODEL 135
SATuration MAGnetization ANalyser
October 2005
SATMAGAN S135 MAGNETIC ANALYZER
GENERAL
Measuring the total magnetic moment of a sample in a saturating magnetic field is a
quick accurate and reliable method of measuring the magnetic material content of the
sample. It is much faster than chemical methods and far more accurate than
measurement based on the susceptibility of the material.
The principle behind the Satmagan is to measure the force acting on the sample in a
magnetic field with a spatial gradient. The magnetic field is strong enough to saturate
the magnetic component in the sample.
A Satmagan can be used to measure any sample with only one magnetic component.
Alternatively, it can measure a component with a dominant concentration and/or
dominant specific magnetic moment.
With a measuring time of roughly one minute and accuracies as good as 0.2 per cent,
a Satmagan is an ideal tool for analyzing mixtures of magnetic and non-magnetic
components.
FEATURES
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Maximum error 0.2% of the measurement range
Analysis time roughly one minute
Two ranges:
0 to 100% of material to be measured
0 to 200% to bring the 100% point to the middle of the scale
Powders and solid samples alike can be measured
The weight of the sample is not critical; generally 1 to 7 grams are used.
Stabilized for voltage and temperature
APPLICATIONS
Analysis of magnetite in iron ores, concentrates and tailings.
The Satmagan was designed specially to measure magnetite in iron ore concentrators.
Magnetite is saturated in the field of the Satmagan and the measurement is made to
the specific accuracy.
Control of copper and nickel smelting by analyzing magnetite and other ferromagnetic
oxides in slag.
The instrument is suitable for controlling sulphide concentrate smelting by measuring
the magnetite content of slag. Satmagans are used at many flash smelters to measure
slags in a copper flash smelter and converters and in a nickel flash smelter and
electric smelter. It is not suitable for controlling slags in a nickel converter, because
ferromagnetic metallic nickel disturbs the measurement. No metallic nickel is involved
in the other stages of smelting.
A Satmagan does not react to magnetite dissolved in the slag. The magnetite has to
be separated to form an independent phase. So the sample must be tempered before
the measurement.
Determination of martensite or ferrite in austenitic steels.
It has been found that the Satmagan is very suitable for measuring delta ferrite and
martensite in austentic steel. In both cases the same calibration curve can be used.
The instrument is also suitable for measuring alpha ferrite.
Determination retained austenite in steels.
The sample is highly ferromagnetic and the percentage of austenite is very small. So
factors affecting the accuracy of the measurement become significant. Satmagan
measurements have successfully been made with steels in which the ferromagnetic
phase represents 0 to 80 per cent of sample.
Control of magnetizing roasting.
Magnetizing roasting is a process in which hematite ore, Fe2O3, is deoxidized by
carbon to yield magnetite Fe3O4, for magnetic concentration. The magnetite can be
measured with a Satmagan.
Control of oxidizing roasting of carbonate ores.
The amount of magnetite in the process can be measured with a Satmagan.
Controlling the heat hardening of pellets.
Pellets made of hematite or magnetite ore and carbon are heated with air to yield iron.
The quantity of iron can be determined from Satmagan measurements.
Control of iron ore sintering.
A bed made of an iron concentrate-carbon mix is heated with air to obtain iron. The
quantity of iron can be measured with a Satmagan.
PRINCIPLE OF OPERATION
The operation of the Satmagan is based on measurement of the magnetic moment m
after the magnetic component in the sample has been magnetized for saturation. The
total magnetic moment is:
m = VMsat
V = volume of the magnetic component in the sample
Msat = saturation magnetization of the magnetic component
In the Satmagan, the magnetic moment is determined by measuring the force acting
on the sample in a non-homogeneous magnetic field – a field having a vertical
gradient of (dH/dz) – and comparing it with the gravitational force acting on the sample:
F/G = [m(dH/dz)]/gmtot
= [VMsat(dH/dz)]/gmtot
= [Msat(dH/dz)]/gp * mm/mtot
F = magnetic force
G = gravitational force (weight)
g = gravitational constant (9.8 m/s2)
mtot = total mass of the sample
mm = mass of the magnetic component in the sample
p = density of the magnetic component
The percentage of magnetic material in the sample is thus:
100 * msat/mtot = 100 * (pg)/[msat(dH/dz)] * F/G
Measuring the ratio of the magnetic to the gravitational force (F/G) and multiplying this
by a coefficient gives the percentage of the magnetic component in the sample.
The proportionality coefficient:
100 * (pg)/[msat(dH/dz)]
Contains natural coefficients (p, g, msat) and an instrument constant (dH/dz).
msat is much better material constant than susceptibility, which is often used in
determining the content of magnetic materials in the samples.
There is no exact linear dependence of the concentration on the quotient of forces at
high concentrations of iron ore magnetite. The measurement is accurate and reliable
but, owing to the non-linearity, a calibration curve is always required.
CALIBRATION
Every Satmagan is calibrated empirically. The output reading of the Satmagan is an
almost linear function of the magnetic material content of the sample. The calibration
curve can be drawn from measurement results obtained with a set of artificial samples
made by mixing pure magnetite and silicon.
SAMPLE PREPARATION
Powders:
It is important for the sample to be dry, because the Satmagan indicates the
percentage of magnetic material in the total weight. In magnetite measurements,
excessive grinding may oxidize the material to a non-magnetic form, especially in dry
grinding. For the same reason, excessive heating during drying should be avoided.
Solid samples:
Samples fitting well into the containers are preferable. For the best accuracy, all the
samples should have the same shape and size.
RESULTS
Accurate analysis of ferromagnetic compounds of iron, such as magnetite, is
extremely difficult and time-consuming by chemical methods. These difficulties can be
overcome by utilizing the magnetic properties of the material. The design and principle
of operation of the Satmagan assure a high degree of precision, combined with a
measurement procedure that is quick and simple.
TECHNICAL DATA
Materials for analyses:
Magnetite and magnetic iron can be analyzed. The sample can contain only one
magnetic component, or have one component with a dominant concentration and/or
specific magnetic moment. Typical applications are listed on pages 1 and 2.
Type of sample:
- solid or powder samples
- maximum volume of sample 1.2cm3 (0.2 cubic inch)
- recommended sample size: sample container filled up (solid or powder)
- grain size: An average grain size greater than 150um (100 mesh) does not
disturb the measurements. For finer materials, the Satmagan gives slightly
lower readings, so a different calibration curve is required.
The range of measurement
- 0 to 100% by weight
- 0 to 200% by weight for high contents
Reproducibility
0.2% by weight
Limit of detection
Usually 0.1% by weight.
Sample containers
- An acrylic container has a sample volume of 1.2cm3 (0.2 cubic inches). Its plug
is made of polyethylene.
- Average weight: container 1010mg, plug 543mg.
- The weight distribution of sample containers is approx. +/- 5mg, corresponding
to an error +/- 0.12% in a 4g sample. The weight distribution of plugs is approx.
+/- 1mg, corresponding to an error of +/- 0.08% in a 4g sample.
Operating temperature range:- +10C to +40C (+50F to +100F)
Ambient humidity :- Up to 95% relative
Controls
- power switch
- range switch
- sample weight balancing knob
- crank for turning magnet
Line voltage
210…240V or 110…130V (to be specified when ordering).
Line frequency
50 to 60Hz
Power consumption
10W
Other data
- Magnetic field around the sample 4 kGauss
- Sensitivity of zero indicator approx. 4mg/mm.
- The instrument can be leveled by means of two threaded feet. There is a
bubble level on the instrument frame.
Overall dimensions
- length 64cm (26in.)
- width 34cm (13.5in.)
- height 37cm (15in.)
- weight 63kg(145lbs.)net.
Export package
- length 97cm (38in.)
- width 56cm (22in.)
- height 56cm (22in.)
- weight 95kg (210lbs.)gross
Further information, quotations, and ordering procedures please contact:INDEPENDENT INSTRUMENTS Pty Ltd
18b Unionway Commercial Centre
283 Queens Road Central
Hong Kong
Phone + 852 2541-0378
Fax + 852 2541-0578
email:[email protected]
www.indehk.com