Utilization of glauconite deposits in Egypt for soil nutrition
Greensand in Bahariya Oasis is often discarded as iron-ore overburden, yet it can serve as a natural potassium fertilizer and soil conditioner.
Glauconite ore
Glauconite, also known as greensand, is a natural mineral found in soils and sediments that holds a good share of potassium. Using it as an alternative and indigenous potassium source rests on several advantages that serve sustainable agriculture.
It is a mining raw material of high economic value across several industries, above all agricultural fertilizers. Egypt holds considerable reserves, yet very few entities are investing in processing the ore to meet the requirements of these specialised industries.
Local alternative source
An ore available inside Egypt that reduces reliance on conventional potassium sources.
Slow-release potassium
Lower solubility than conventional fertilizers means less loss by leaching.
Healthier soil
Improves soil structure and water and nutrient retention without acidification or salinization.
Micronutrients
Supplies plants with iron, magnesium and traces of other elements.
Glauconite deposits in Egypt
Two main studied occurrences: El-Gedida iron mine in Bahariya Oasis and Abu Tartur mine in the Western Desert (about 650 km south-west of Cairo).
glauconite thickness above El-Gedida iron ore
Hamra Formation age
Ore reserves
In Bahariya Oasis the glauconite lies directly above the iron ore, so reserve data and infrastructure are tied to the region’s iron mines.
proven geological iron-ore reserve, El-Gedida mine
design capacity of El-Gedida (output up to ~3 Mt)
in 3 unexploited mines, El-Harra & El-Gorabi
average Fe after homogenization (up to 54.76 % in Soviet studies)
Geology
Ores occur in the Bahariya Formation (Early Cenomanian, Late Cretaceous), a fluvio-marine sequence of sandstone, shale and claystone. They are stratiform deposits of hematite, goethite and limonite; main areas are El-Gedida, El-Harra, El-Gorabi and Gebel Nasser.
Mineralogical & chemical properties
El-Gedida glauconite is a mature, evolved type, rich in potassium and of high purity.
| Oxide % | El-Gedida E | El-Gedida W |
|---|---|---|
| SiO₂ | 52.10 | 50.89 |
| Fe₂O₃ | 22.23 | 22.99 |
| K₂O | 6.75 | 7.30 |
| Al₂O₃ | 5.99 | 5.88 |
| MgO | 3.75 | 4.34 |
| P₂O₅ | 0.14 | 0.07 |
High purity
Pellets 97.81 % (E) and 98.32 % (W); impurities mainly quartz, alunite, halloysite, calcite.
Optimum size
The −250+125 µm fraction is 81.74 % / 73.94 % of the ore and holds the highest K (up to 7.38 % K₂O).
Beneficiation by sieving
Gangue is harder than glauconite and concentrates in fines, so sieving alone is enough.
Surface properties
Surface area 47–62 m²/g, porosity 12–19 %, CEC 5–40 meq/100 g (Abu Tartur).
Soil nutrition: a natural potassium alternative
Glauconite has been used as a potassium fertilizer for over 100 years, and El-Gedida material meets the published fertilizer criteria.
Slow-release potassium
Lower solubility than KCl/K₂SO₄ means less leaching; release improves when mixed with compost.
Soil structure
Uniform grains, high cation exchange and pellet micropores raise water and nutrient retention.
No acidification or salinization
pH 6.71–7.59 and salinity 0.056–0.128 dS/m, far below nitrogen fertilizers (up to 12 dS/m).
Micronutrients
Supplies Fe, Mg and traces of Zn, Co, Ni, Mn that support metabolism and N-fixation.
Land reclamation
Suited to new sandy lands thanks to water and nutrient retention.
Optional thermal activation
Roasting with CaCl₂ at 750–850 °C converts K into leachable KCl.
Heavy-metal safety (ppm)
| Sample | Cu | Pb | Zn | Ni | As | Cd | Co | Cr |
|---|---|---|---|---|---|---|---|---|
| El-Gedida E | 3.7 | 2.0 | 86 | 15.4 | 2.4 | <0.1 | 25.8 | 110 |
| El-Gedida W | 2.4 | 0.3 | 208 | 30.7 | 2.2 | <0.1 | 28.0 | 130 |
| CFIA limit | 400 | 150 | 700 | 62 | 13 | 3 | 34 | 210 |
All eight elements in both El-Gedida samples are below the CFIA limits, so the Bahariya Oasis ore meets the CFIA heavy-metal specification. Agronomic performance still needs field trials on Egyptian crops.
Applications by plant type
Proposed Agri-K-Organic product line by use.
Non-agricultural applications
Beyond fertilizing, glauconite has several industrial and environmental uses.
Water treatment
Manganese-coated greensand removes iron, manganese, zinc and lead from groundwater and wastewater.
Environmental remediation
Adsorbs heavy metals and other pollutants from soil and water thanks to its layered structure and ion-exchange capacity.
Natural pigments
“Green earth” is a mineral pigment for paints, art and coloured concrete.
Ceramics & glass
A colourant and flux in glazes and some green glass.
Construction
A mineral additive and colouring agent in some building materials and decorative concrete.
Drilling & industry
Used as a filler and mineral additive in some drilling fluids and industrial applications.
* General industrial uses; each needs testing and characterization for the Egyptian ore.
Value chain
Turning mine overburden from waste into a fertilizer product.
Mining
Recover greensand during overburden stripping.
Comminution
Crush and grind to −1 mm; simple grain contacts ease liberation.
Sieving
Take the −250+125 µm cut and reject clay fines.
Quality control
Test K₂O, heavy metals, pH and salinity.
Products
Agri-K-Organic: natural K fertilizer and soil conditioner.
Packaging: 25 kg bag
The finished product is packed in 25 kg bags on an automatic, precision-weighing line.
Bag weight
Approx. weighing error
Frequently asked questions
Quick answers about glauconite and the Agri-K-Organic product.
What is glauconite (greensand)?
A natural green mineral found in soils and sediments that holds a good share of potassium. Agri-K-Organic turns Egyptian glauconite from Bahariya Oasis into a natural potassium fertilizer and soil conditioner.
Is it safe? What about heavy metals?
All eight heavy-metal elements tested in both El-Gedida samples are below the CFIA limits. See the heavy-metal table on the Soil Nutrition page.
How is it different from conventional potassium fertilizers?
Glauconite releases potassium slowly, so less is lost by leaching. Its pH (6.71–7.59) and salinity (0.056–0.128 dS/m) are low, so it does not acidify or salinize the soil, and it also supplies iron, magnesium and trace elements.
Which plants can it be used on?
The proposed product line covers flowers, vegetables and fruit, trees and shrubs, houseplants and lawns. It also suits new sandy lands because it retains water and nutrients.
Where does the ore come from?
From the El-Gedida area in Bahariya Oasis, where roughly 25 m of glauconite lies above the iron ore and is usually stripped as overburden.
How is the product packed?
In 25 kg bags on an automatic, precision-weighing line.
What application rates and field results are available?
Lab results are strong, but agronomic performance still needs field trials on Egyptian crops. Contact us for technical guidance on your soil and crop.
Can I order or request a quote?
Yes. Use the Contact page with the quantity you need and your location.
Contact us
For enquiries, quotations or technical guidance, send us a message and we will get back to you.