Nkombwa Mountain is our most promising phosphate project (Fig. 1). It is located in North-Eastern Zambia, close to the borders of both Tanzania and Malawi and northern Mozambique, close to infrastructure (power, water, telecoms, road & rail). Nkombwa was first recognised in the 1960’s but due to certain inhibiting factors, it has largely been ignored until very recently. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1.  Rising 1100 feet (335m) above the surrounding savannah, this extinct volcano, “Nkombwa Mountain” impresses in its imposing massif.  Not obvious to the casual observer are the centuries of food security offered by its Agri-nutrient composition.

 

 

TESTING NKOMBWA

In 2012, the current licence-holders had the vision to scientifically re-assess Nkombwa, and do so in far more detail than before, with all options of modern technology at their disposal.  This grouping, endorsed and encouraged by COMESA (Common Market for Eastern and Southern Africa) at all stages has now branded itself “African Agronomix Ltd” or “AAX”– as registered in COMESA states & the UK.

 

Early results were promising, indicating that Nkombwa Mountain likely contained ore-grade rock for both Phosphates and Rare Earth Elements (“REE’s”).  Development of the Resource has included helicopter-borne geophysics surveys, geochemistry work based on rock-channel sampling across the top of the mountain and the re-assessment of old drill cores located in the Kalalushi archive yard.

 

In 2015 a drilling programme was designed, roads cut to the top of the mountain and water infrastructure developed to supply drill rigs.  The logistics challenges were severe given the complete virgin nature of the location and the sheer size, scale and steepness of the mountain.

 

Drilling commenced Nov 2015 on the northern most crescent of the Nkombwa Mountain, continuing through May 2016 (Fig. 2).  The drill core rock component extracted was split and a representative 25% of all rock was shipped to Intertek – Genalysis of Perth, Australia for a full assay of elements.

 

 

 

 

 

 

 

 

 

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Figure 2. Drill-core extracted – ready for splitting & assay – May 2016

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Drilling is an expensive exercise and with natural budget constraints the programme was focussed on just 5% of the above-ground volume of the Mountain.  It was assessed that the chosen 5% would likely be somewhat representative and that indications of the entire Mountain’s makeup could be extrapolated with some degree of accuracy from the first 5%.  Furthermore, the consensus was and is that, should the results be promising, funding would be sought to complete the exercise in due course.

 

The assay results of every linear metre of rock extracted were collated, interrelated by independent, certified professionals using specialised software to spatially model a 3-D representation of the ore-body as is accepted best practice (Fig. 3).  The same professionals worked to the specifications of the Australian Joint Ore Reserve Committee (“JORC”) the most globally recognised standards body for Mineral Reserve Reporting. 

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Figure 3. Plan-view 3D depiction of Nkombwa Mountain showing the drill holes which allowed AAX to assess the contents of 5% of the above-ground volume.  The zones outside the blue outline offer Phosphate-enriched residual soils at the foot of the Mountain

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THE RESULTS

The final results have exceeded all expectations with a JORC Resource certified at nearly 22 million tonnes of likely economic Rock Phosphate ore existing within just 5% of the Mountain as assessed and probably less than 2% of the entire ore body considering thee rock below surface of valley floor.

 

In addition, within the greater 22m tonnes, the exercise defined 3 million tonnes of high grade REE ore, which will add to the economic viability of the project.  A further 5 million tonnes of “waste” consists of mostly clean dolomite, which has been assessed in the past and offers high-quality agricultural lime.

 

Many Phosphate deposits are cursed with coincident contaminants such as Uranium, Cadmium or Thorium that are dangerous for human or animal consumption – and these can be expensive to remove in the process of fertilizer manufacture.  To ensure no wasted money, AAX first ensured that the Nkombwa Mountain ore was free of such contaminants.  Indeed it is free of any problematic levels of toxic chemicals, providing confidence in likelihood of economically viable processing.  The assessed gross value within only the 5% tested to date is $5.4 billion including Phosphate & the two key REE’s – see chart in Fig. 4.

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Figure 4. Break-down of in-situ gross dollar values of the 5% of above-ground as drilled at Nkombwa

 

Volcanoes come up from the mantle of the earth.  The magma brought up to surface by this Nkombwa volcano (extinct for ~700 million years), brought with it the valuable Phosphates & REE’s.  The core of the volcano still reaches down through the crust to the mantle, and as such we can safely assume that the ore goes about 20 kilometres deep – way beneath the deepest economically viable mining depth. As it transpires, in 1967 a company decided to drill two holes below the mountain looking for copper. AAX has been able to find these drill positions and drill-holes and has located the actual drill-core extracted – perfectly preserved in the outstanding archives controlled by the Zambian Government.  More than 1,000 metres of this rock core was assayed and assessed using the same Australian Laboratory.  These results confirmed that high grade Phosphate & REE’s continue at depth below the visible Mountain.

 

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EXPECTATIONS FOR THE FUTURE

With the extrapolation of the 5% to the rest of the above-surface mountain, plus with the knowledge gained from the old holes below the mountain, AAX has grounds to consider that the ore body may contain between 400 and 800 million tonnes of ore which could be viably mined and processed into fertilizer product over many decades or centuries. 

 

Different fertilizers obviously have different levels of Phosphate percentages so one has to set a benchmark from which we are to work.  The commonly accepted standard in mining and in agriculture used in the representation of percentage Phosphate refers to percentages by weight in any measured mixture / compound / ore / fertilizer of contained Phosphorous Pentoxide (P2O5). At the percentage grades in situ, and using Zambia’s current agricultural consumption as a marker, it is reasonable to assume that Nkombwa houses extractable P2O5 sufficient for well over one thousand years of Zambia’s annual consumption.  Based on calculations that have some margin of error, Nkombwa could comfortably supply the whole of sub-Saharan Africa for over one hundred years.   Clearly this is a landmark discovery.

 

In terms of proving that Zambia hosts at least one world-class deposit of valuable Agri-minerals, the task is complete.  In terms of advancing this knowledge to a practical, commercial use as a new, domestic player in the fertilizer industry, Nkombwa provides a key cornerstone on which the foundations of this industry may be based.

 

Phosphate Rock could, of course, be concentrated, exported & sold overseas to fertilizer manufacturers – whereupon it would be beneficiated and sent back to Africa as fertilizer.  The cost involved would be economically nonsensical and the carbon footprint morally indefensible.  Nkombwa was never intended to be a mine only and as its name suggests, African Agronomix Limited is not a mining company.  AAX is an agricultural supplies company who aims to vertically integrate, control its own access and ownership to the raw materials from which its products are derived – a “Mine-to-Market” approach with strategic supply-lines. Domestic beneficiation with entirely domestic inputs is the aim and tests have already commenced on Nkombwa ore for optimisation of treatment techniques – a treatment, which includes several phases as demonstrated in the flow diagram in Fig. 5.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Figure 5. Converting Phosphate ore into useable fertilizer

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OTHER PHOSPHATE SITES

It has long been suspected that Nkombwa is the largest higher-grade Phosphate deposit in the region, as has now been conclusively proven by AAX, but it is not the only site in Zambia where the mineral has been identified.  AAX has concluded one agreement controlling half of the second largest Zambian Phosphate deposit (Kaluwe South), and negotiations with the remaining two licensees, on two proximal deposits (Kaluwe North & Chilembwe) are at advanced stages. The location of all these deposits and of Nkombwa is shown below in Figure 6 and 7.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 6.  Geology of Phosphates, (& of Gasifier/Haber Process (Nitrogen) feedstock (Coal), see Nitrogen projects)

 

 

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Figure 7. Locations relative to Infrastructure (*Sinazongwe see Nitrogen projects)

 

It is anticipated that although far smaller, these may offer two complimentary benefits to the Nkombwa deposit:

(a) Geography – being closer to the Lusaka & Southern Province markets & the Nitrogen-feed sites; and

(b) Historical work on Kaluwe specifically has indicated presence of reasonable tonnage of residual, Phosphate-enriched surrounding soils, which in historical test work indicated amenability to low-cost beneficiation to fertilizer….  and if confirmed this would offer a low-cost, low-capital start-up operation which could commence production and sales while the larger rock mining operations at Nkombwa completes construction.

Consolidating all possible economic deposits under one roof creates a better, unified force behind this movement.

 

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ADDITIONAL AGRICULTURAL BY-PRODUCTS

The process of beneficiation of the Phosphate Rock to produce the various phosphate fertilizers plus the use of “waste” dolomite from Nkombwa offers up a surprising medley of agricultural by-products which are all in demand in Zambian and regional agriculture, and mostly imported.  They include:

• Gypsum (Calcium Sulphate): a nutrient and soil-conditioner, currently imported and landing at $100/t

• Phospho-Gypsum (also Calcium Sulphate but with P2O5 credits): currently no supplier in the region​

• Kieserite (rough Magnesium Sulphate): for blending, soil-chemistry stabilisation (Magnesium with Calcium facilitating P2O5 uptake by crops), offering Magnesium and Sulphate nutrients, currently imported from Germany.​

• Crystalline Epsom Salts (A higher grade Magnesium Sulphate): priced at over $1500/t, currently imported from RSA and China.​

• Agricultural Lime / Dolomite: A neutraliser of highly acidic soils (i.e. low pH) which are a serious regional problem, mostly imported with small domestic suppliers

• Safe Organophosphate pesticides