report for chemicals producers

7/30/2019 Report for Chemicals Producers

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A BRIEF TO BOARD MEMBERS ON INDUSTRIAL CHEMICALS

Dear Members,

Please find my comments, as follows:

1. Additional Mining Chemicals that can be manufactured in the Pacific Islands.

These chemicals are widely used in Fiji, The Solomon Islands, The

Philippines, Indonesia and Papua New Guinea, all of those countries

prepared to purchase based on price and not manufacturing conditions.

Frothers:

o Pine Oil

o Palm Kernel Oil (PKO)

o Eucalyptus Oil

o Creosote

Collectors:o Fatty Acids collectors, also known as Tall Oil collectors

o Alkyl Sulphate and Alkyl Sulphonate collectors

o Phosphoric Acid collectors

o Sulphosuccinates and Sulphosuccinamates collectors

Depressants:

o Sodium Silicate (Na2SiO3), also called water glass. Used as a gangue

depressant. You remember I said that the linger chain Xanthates can

float unwanted and nasty minerals, thus depressing the product grade.

Sodium Silicate can then be used to depress those nasties during thecleaning stage, to enhance the grade and make a saleable product.

o Zinc Sulphate (ZnSO4), used to depress sphalerite (ZnS) and talc

during lead/zinc flotation.

o Sodium Carbonate (Na2CO3), used as zinc depressant on some

lead/zinc flotation plants.

Activators:

o Copper Sulphate (CuSO4). During our conversation, you mentioned the

use of copper sulphate as a depressant. Ive used it as an activator for

zinc, iron and slow floating sulphide minerals of those metals. The

mechanisn is the creation of an artificial layer of copper sulphide, one

molecule thick, and those minerals now float like the more amenable

copper sulphide. This is synonymous to cementation.

o Sodium Hydrosulphide (NaHS). Used in the activation of copper

oxides. Here again, we create an srtificial layer of copper sulphide, and

fool the oxide minerals to float as if they were a sulphide.

o Sodium Sulphide (Na2S), used to activate zinc minerals in lead/zinc

flotation. Also has the additional benefit of modifying the pH value of

the pulp.


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pH Modifiers:

o Lime (CaO), the cheapest source of increasing the pH value of

processing palnt pulp.

o Soda Ash (Na2CO3), also used for increasing pH value of a pulp.

o Sodium Hydroxide (NaOH), also called Caustic Soda. Used for

increasing the pH of pulp. Its greatest use is in the Bayer Process,

where it is used to dissolve alumina (Al2O3) from bauxite. That alumina

is later precipitated as alumina hydroxide (Al(OH)3), then calcined to

drive of the chemically bound water leaving crystalline Al2O3, as pure

alumina, which is subsequently smelted into aluminium metal using

electricity.

2. Changes in Mining Processing:

You did ask as to why the mining process has changed now, compared to the past. I

mentioned that the easier mineable, and processable ores have become exhausted.

As a result, we are now mining lower grades, and deeper orebodies. Result from

such paradigm shift, the processing had to evolve. The amount and type of reagent

traditionally used, had to be changed. This is summarised in the photomicrograph

shown in Figure 1. This shows the minerals found at the Mount Isa mine in

Queensland, Australia. The left image, with the larger crystald, was the old orebody

which is now depleted. The right image, shows the current orebody. To profitab;y

extract such fine grained valuable minerals, the ore had to be ground finer, and

different mining chemicals used in the extraction process. It is for this reason that we

collaborate with mining chemicals manufacturers, hoping to build a symbiosis which

is mutually beneficial to both of us.

Figure 1: Photomicrograph showing difference in ore types, within the same

orebody. This is Mount Isa lead/zinc mine in Australia. The image on the left

shows the upper orebody, the one on the right, the lower orebody. Different

flotation reagents regime will be required for efficient flotation separation


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3. Froth Texture:

When we were discussing frothers, I spoke about froth texture, and the need for

the froth to break easily. The following images, Figures 2, 3 and 4 explain the

concept much better. Hopefully, this stresses the imperative of correct frother

selection.

Figure 2: A tight and nuisance froth, nasties will get trapped and depress the

grade of the final product

Figure 3: An improved froth, manageable, but not perfect


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Figure 4: The perfect froth. The imploding bubble (at 1 Oclock position) and

clear patches on the bubbles, indicating incipient collapse and the ease of

breakage of the froth

4. Xanthate Safety:

Since Xanthate is manufactured from carbon disulphide (CS2), the concomitant

spontaneous combustion hazard must be weary of. Adequate post-production airing

time must be allowed for, prior to packaging. Figures 5-9 show the ensuing result if

such practice is not rigidly adhered to!

Figures 5 and 6: Spontaneous combustion of Xanthate


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Figures 7 and 8: Spontaneous combustion of Xanthate

Figure 9: Spontaneous combustion of Xanthate, stressing the need for ample

aeration prior to packaging

5. General Overview:

As metals prices decline, Figures 10 and 11, plant operators need to maximise the

recovery of valuable minerals form the ore mined. This can be only achieved through

the judicious and astute use of the best mining chemicals they can get. After all, the

majority of cost is incurred in getting the ore to the mill!


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Figure 10: One-mo

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