In the development of human society, the invention of the steel plays a very big role. Even now, the production of steel is still a very important figure to measure one country's industrial development level. Before smelting the steel, the technology to improve the grade of Iron ore to match the steel industry's demand is becoming more and more important for every country. Zenith is with strong technical stength to be your support to do the Iron ore processing. Here is the brief introduction of iron ore pcorssing technology as below:
1. The brief introduction of Iron ore
Broadly speaking, all the stone which
contains Fe elements can be named iron ore. From the narrow sense, only the raw ore which can reach the
standard of industry requirements or can reach the standard after processing can be named Iron ore. The
main type for steel smelting is Magnetite (Fe3O4), hematite（Fe2O3）, siderite（FeCO3）,etc. Fe is always
exists in nature by the state of the compound and It occurs chiefly as the dioxide. Here is the
specification of the above Iron ore.
| Name | Content | Specific gravity | Color | Theoretical grade | Cutoff grade | Production grade | Remark |
| Magnetite | Fe3O4 or FeO·Fe2 O 3 | 5.15 | Dark gray | 72.40% | TFe≥ 20%, mFe ≥ 15% | TFe≥25%, mFe≥20% | |
| Hematite | Fe2 O 3 | 5.26 | Dark red | 70% | TFe≥25% | TFe≥28% | |
| Siderite | FeCO3 | 3.8 | Steel grey | 48% | TFe≥20% | TFe≥25% | |
| Limonite | Fe2 O3·nH 2 O | 3.6～4.9 | Ocher or brown | 62.90% | TFe≥25% | TFe≥30% | |
| Note: If the Magnetie contain too much ironsilicate, ironsulphide and iron carbonate, please use the mFe standard. | |||||||
2. The processing technology for above iron ores:
Nearly for all the Iron ores,
need crush and grind the mineral ore into the suitable size before the beneficiation processing. The
crushing section and grinding section for all of them will be almost same. So we will pay more attention
on introduce the beneficiation processing technology.
Magnetite: a. Low intensity magnetic
separation (LIMS) technology.
b Low intensity magnetic separation technology+ flotation process
Hematite: a. High intensity magnetic separation technology;
b. Reduction roasting
process+Low intensity magnetic separation technology
c. High intensity magnetic separation
technology+gravity treatment process+flotation techniques
Siderite: a. High intensity magnetic
separation technology
b. Neutral roasting process+low intensity magnetic separation technology
c. Flotation process or Flotation + high intensity magnetic separation technology
Limonite: a. High intensity magnetic separation techniques
b. Roast reduction process+ Low
intensity magnetic separation techniques
c. High intensity magnetic separation techniques+
flotation techniques
3. How to setup the Iron ore processing plant?
Frist, doing the
geological prospecting to know the
deposit, position and the trend of your mine and make
sure it is with the the feasibility of developing or not.
Second, doing the dressing test
is for choosing the suitable and economical mineral processing technology and recovering the Cu element
inside the raw ore after detailed experimental study. The research report will be as the basis of the
project feasibility study.
a. Spectral analysis & elements chemical analysis to fix the
chemical composition of Iron ore
| Elements | Tfe | SiO2 | TiO2 | Al2O3 | Fe2O3 | FeO | MgO |
| Cotent % | 34.48 | 43.63 | 0.02 | 1.04 | 29.14 | 18.39 | 2.17 |
| b. Iron ore phase analysis to fix the type of your Iron ore ( magnetite, hematite, siderite, limonite or other type) | |||||||
| Item | TFe | mFe | Ferrosilite | Ironcarbonate | martite | hematite & limonite | Magnetic iron share |
| Content % | 35.15 | 29.76 | 3.22 | 1.56 | 0.33 | 0.28 | 84.67 |
From the above table, the content of mFe is 84.67 of the total Fe. It tell us the magnetite is
oxygenated.
c. The texture and structure and mineral composition of the ore; To know the valuable
mineral of your Iron ore like the magnetite, marite and the gangue which is associated with the Iron ore
like, quartz, calcite, siderite, hornblende, actinolite, grunerite, etc.
| Item | Essential mineral | Auxiliary minerals | Tiny traces of minerals |
| Valuable mineral | Magnetite | martite | hematite, limonite |
| Gangue mineral | Quartz | calcite, siderite, hornblende | actinolite, grunerite |
d. The major metal mineral's embedded features; The Major element mineral's granulometric composition and distribution characteristics;
| Partical size (μm) | 2000-1168 | 1168-833 | 833-589 | 589-417 | 417-295 | 295-208 | 208-147 |
| Iron Ore | 0.18 | 0.34 | 0.55 | 0.56 | 1.16 | 3.75 | 6.16 |
| Gangue | 1.51 | 2.4 | 5.07 | 5.88 | 7.41 | 8.97 | 8.42 |
| Partical size (μm) | 147-104 | 104-74 | 74-43 | 43-35 | 35-15 | 15-10 | 10-0 |
| Iron Ore | 10.85 | 12.87 | 18.41 | 10.2 | 26.64 | 7.52 | 0.26 |
| Gangue | 8.82 | 8.4 | 12.79 | 6.36 | 18.66 | 5.06 | 0.25 |
| Particle mean size | Iron Ore | Gangue | |||||
| Content % | 38.54 | 51.68 | |||||
From the above table, the particle mean size of Iron ore is 40.06 μm and the particle mean size
of gangue is 51.68 μm. Between the partile size of Iron ore -417 μm is around 97.82% It is easy to
get rid of the gangue.
e. The different grinding size under low intensity magnetic separation
(LIMS) - high intensity magnetic separation (HIMS) test for fixing the suitable grinding size.
| -74μm Passing Rate % | Products | Yeild Rate % | Grade % | Recovery Rate % | Remark | ||
| 44.8 | LIMS Concentration Ore | 20.7 | 55.5 | 40.57 | |||
| HIMS Concentration Ore | 40.72 | 36.4 | 52.33 | ||||
| Tailings | 38.58 | 5.2 | 2.01 | ||||
| Raw Ore | 100 | 28.32 | 100 | ||||
| 53.3 | LIMS Concentration Ore | 19.66 | 57.5 | 39.82 | |||
| HIMS Concentration Ore | 39.38 | 38.1 | 52.82 | ||||
| Tailings | 40.96 | 5.1 | 7.36 | ||||
| Raw Ore | 100 | 28.4 | 100 | ||||
| 63.8 | LIMS Concentration Ore | 19.51 | 58.9 | 40.6 | |||
| HIMS Concentration Ore | 38.94 | 38.75 | 53.32 | ||||
| Tailings | 41.55 | 4.15 | 6.08 | ||||
| Raw Ore | 100 | 28.3 | 100 | ||||
| 82.9 | LIMS Concentration Ore | 17.39 | 62.82 | 38.59 | |||
| HIMS Concentration Ore | 36.5 | 42.08 | 54.28 | ||||
| Tailings | 46.11 | 4.38 | 7.13 | ||||
| Raw Ore | 100 | 28.3 | 100 | ||||
| 90.7 | LIMS Concentration Ore | 17.1 | 64.95 | 39.12 | |||
| HIMS Concentration Ore | 33.77 | 45.3 | 53.87 | ||||
| Tailings | 49.13 | 4.05 | 7.01 | ||||
| Raw Ore | 100 | 28.4 | 100 | ||||
According the customer's target grade of final Iron ore can chose the suitable grinding size. Fox examble, the customer want to get the magnetite ore with grade 57.5% and the hematite with grade of 38.1% and the total recovery rate reach 90%. It can just use one stage ball mill grinding for saving the cost.
f.Exploratory Test; Make exploratory Test for the ore and make foreshadowing for condition test; If your
Iron ire is rich in the Ti2O3, Cu, S, we can give you the advice to expand the production in the future.
g. Condition test; Base on the research, we will doing the condition test include grinding
solution; grinding fineness; magnetic separation and flotation concentration solution; collector type
and dosage; depressant type and dosage; activator type and dosage; modifier type and dosage; PH value;
flotation time; pulp density, etc for fixing the technological parameter of beneficiation flowsheet;
h. Completely open closed-circuit test: Base on the above test, choose the beneficiation
technology process and the process parameters. The test index should be with repeatability, stability
and facticity.
i. Product check: Make multi-element analysis for the concentrate and tailing;
Make sedimentation performance test for the concentrate and tailing.
j. Designing the
beneficiation flow-sheet:Base on the above test, designing the most suitable beneficiation
flow-sheet,technological parameter and reagent system.
k. Issuing Report Issuing report base on
the above tests.
Third, choosing the suitable equipments base on the above test result.
Forth, build the foundation and doing the installation with our engineer. After receiving the deposit,
we will send the technical drawing to you and send our engineer to supervise the foundation building and
guide your staff to do the installation, then have a commissioning running. Meanwhile, they can train
your staff at your site also.
4. Here is one project of Magnetite ore processing plant for your reference. Please see the flow
chart of crushing section and the grinding and beneficiation sections.
a. In the
crushing section, we use our PE900x1200 jaw crusher to crush the Iron ore from 800 to 220 mm and then
use the s series cone crusher to crush the Iron ore into size 0-10mm. We use the belt conveyor for final
output Iron ore with magnetic pulley to pre-taking out a part of waste rock before feeding ore into ball
mill. It can imprpove the magntite ore with grade 3-6% higher and reducing the ore feeding of ball mill.
b. The crushed ore with size 0-10 mm will be fed into the wet grid type ball mill to grind it.
And slurry will be classified by the spiral classifer. The particle with size above 0.52 mm will be
returned to the ball mill to grind it again.
c. The particle with size minus 0.52 mm will be sent
to the wet type low intensity magnetic separator (LIMS) ZCT-B1200x3000 to do the roughing first. The
rough concentration ore will be sent to the tank, then it will be sent to the high frequency ming screen
ZD5FG1216 to classify. The taillings will be sent to the tailing pool to wait for the concentrate
processing by the inclined plate thickner.
d. The rough concentration ore will be sent to the
high frequency ming screen to classify. The particle with size above 0.21 mm will be processed by the
LIMS ZCT1200x3000 to do the dewatering magnetic separation. The concentration ore will be sent to the
wet overflow type ball mill to grind it. The tailing will be sent to the tailling pool.
e. The
particle with size minus 0.21 mm will be sent to the LIMS separator ZCT-B 1200x3000 and ZCT-B1050 to do
the two stage cleaning. The tailing we will send to the tailing pool. The final concentration ore will
be sent to the permanent magnet filter ZGYW-16 to do the dewatering. The dry concentration ore will be
the final products.
"f.All the tailings in the tailing pool will be sent to the tailings
recycling machine ZTLWK-8008 to do the scavenging. The concentration ore from it will be sent to the
rough cocentration tank wait for cleaning process.
"
g. All the tailings will be
dewatered by the inclined plate thickner ZNXB600/55. The tailings after dewatering will be with the
water content around 24%. The tailings slurry will be transported to the tailing lake by slurry pump.
h. The above design is the complete plant for magnetite ore processing plant. The customer can
get the magnetite powde as the final product. Some customer will choose the pelletizer to make iron ore
ball or block and then doing the sintering process.
From the above project case, like the prticle
size, water consumption, the pulp density and the processing capacity of each equipments and the
magnetic intensity should be fixed after doing the above dressing test. If it is without the dressing
test, nobody can ensure the whole plant's performance. That's why we always advise our customer to do
the dressing test and get the dressing test report, then we can give you the quotation list with full
deails. After many years, Zenith have full experiences to work together with the famous labratory in
China to supply the full solutation to our distinguished customer. We do beleive that we will enjoy your
trust by our professional and quality control.
5. Appendix I: The flow chart for the magnetite processing plant ( Crushing Section )
