254 



The Philippine Journal of Science 



1914 



now being discarded as unsuited to the present smelting process. 

 Obviously, this siliceous ore should be utilized ; it can be utilized, 

 and at the same time the required increase of silica in the slag 

 can be effected by blending it with the pure ores. 



Limestone, which will be required as a flux if modern methods 

 are introduced, is available in the vicinities of all the ore deposits. 

 The Binangonan limestone is most uniform and widespread, 

 and would make an efficient flux. Analyses of the Binangonan 

 limestone, together with an analysis of the residual clay which 

 serves as a flux in the present smelting process, appear in the 

 following table. 



Table XL — Analyses of Binangonan limestone and a residual clay, Bulacan 



iron ore region. 



Constituent. 



Sample No. 



6-45.» 7-45.a 33.b 



Moisture 



Silica (SiOo) 



Ferric oxide (FeaOa) - 



Alumina (AljOa) 



Lime (CaO) 



Magnesia (MgO) 



Potash (K2O) 



Sodium oxide (NajO). 

 Loss on ignition 



Total 



0.12 

 L25 



0.38 



0.26 

 0.61 



0.52 



100.28 



53.01 



63.98 



1.38 



1.12 



0.14 



0.11 



0.62 



0.46 



43.38 



43.44 



t.l5 

 58.61 



7.39 

 23.31 



0.90 



0.99 



trace 



1.94 



100.50 



95.29 



* Binangonan limestone, vicinity of Bagum Barrio ; analyzed by L. A. Salinger, chemist. 

 Bureau of Science. 



i* Clay from decomposed granite near Hison ; analyzed by T. Dar Juan, chemist. Bureau of 

 Science. 



Cost and value of iron produced. — The cost of a smelter fully 

 equipped varies from 900 to 2,500 pesos. If the site is distant 

 from clay suitable for furnace and mold construction, if two 

 furnaces are erected and the smelter is roofed with sheet iron, 

 the cost approaches the higher figure. If the furnace clay is 

 at hand, if only one furnace is erected and the roof is made 

 of palm leaves or grass, the smaller sum will suffice. 



The cost of smelting and marketing the castings varies with 

 the distance of the smelter from charcoal, ore and clay deposits, 

 and from market. 



The cost of charcoal varies from 10 to 20 pesos per metric 

 ton, equivalent to about 90 bushels. An average cost based on 

 the actual expenditure for 4 separate kilns is 14.75 pesos per ton. 



The cost of transportation from smelter to market varies from 

 0.05 peso to 0.30 peso per pair, depending on the distance 



