GUANO PHOSPHATE

Phosphate is one of the minerals formed in guano which contains the element PO2O5. Phosphate is the only mineral (outside of water) that has a cycle, the phosphorus element in nature will always be absorbed by living creatures, phosphate compounds in the tissue of dead living creatures will decompose, then accumulate and be deposited in the ocean. There are three types of phosphate deposit formation processes, namely:

Primary phosphate, formed from the freezing of alkali magma in hydrothermal vein intrusions which is sometimes associated with alkaline igneous rocks containing apatite phosphate minerals, especially fluorapatite (Ca5 (PO4)3 F) in its pure state contains 42% (P2 O5) and 3.8% ( F2).

Marine secondary phosphate, is a sedimentary phosphate deposit that is deposited in the deep sea, in an alkaline environment and calm atmosphere, the phosphate minerals that are formed are mainly francolite. Marine sediments are formed from the decomposition of various life in the sea, or due to the erosion of minerals containing phosphate by river flows which are then carried out to sea and sedimented with limestone. Phosphate/phosphorus particles will clump and settle as pellets on the seabed. As a result of geological events, sediment will be lifted and form land. The deposits that occur often reach very large areas with a thickness of tens of meters. Usually phosphate deposits form layers or pellets between limestone.

Terrestrial secondary phosphate/guano, is the result of the accumulation of secretions from land animals, fish-eating birds and bats which dissolve and react with limestone due to the influence of rainwater and groundwater. This type of deposit is usually found on islands that have little rainfall, so erosion almost never occurs. Guano phosphate deposits come from bat droppings deposited in limestone caves. This dirt containing phosphate acid reacts with limestone and calcium carbonate rocks. The reaction that occurs will form calcium phosphate as a result of metasomatic replacement of limestone. If this occurs in clay containing iron and aluminum, the reaction will produce Fe phosphate and Al phosphate. Phosphate guano is not good as a raw material for making TSP (Triple Super Phosphate) and DSP (Diammonium Super Phosphate) fertilizer because phosphate guano contains high levels of Al and Fe impurities so that these elements really interfere with the process of using TSP and DSP fertilizers.

Based on field surveys, the potential for phosphate is in Banyuurip Village, Gresik District, namely on Mount Kaklak. Phosphate was found in limestone walls covering an area of ​​21.4 ha. Phosphate is generally used as fertilizer, both artificial fertilizer and natural fertilizer for acidic soil, and as a mixture for making detergents, phosphoric acid and other chemical industries.