Marathon lease

Procedure. The laboratory work described here was performed with two shale samples one consisted of material from cores taken at a depth of 1830-1860 feet from the Marathon lease and the second in the form of rock fragments from the Colony mine (Dow property). 

Organic binder was added to the aqueous slurry and the process was continued as described above. Results of duplicate experiments are shown in Figure 2. The beneficiation obtained with this Dow-Colony shale is less favorable than that with Marathon lease material. 

Figure 1. Recovery of Marathon Lease kerogen as a function of the number of beneficiation cycles. (Kerogen determined by weight loss on low-temperature ashing.)...

Dow-Colony leases. The sums of the weight percent of the Ca/Ca-Mg carbonates and pyrites in the Marathon samples lie between 30 and 35 percent whereas in the Dow-Colony samples, they lie between 47 and 80 percent. This observation supports the finding that the superior upgrading of the Marathon lease shale is due to its lower carbonate/pyrite content. 

TABLE III. MINERAL CONSTITUENTS OF MARATHON LEASE AND DOW-COLONY MINE SHALE SAMPLES (Estimated Weight Percent in Crystalline Portion)... 

Sodium bicarbonate Marathon lease samples which exhibit high levels of beneficiation also contain nahcolite (NaHCX ). 

Product Assay. Fischer Assays were performed with samples of Marathon lease material, with both raw shale and with the beneficiated pellets. Spent shale (char) from the assay was subjected to heat value (Btu content) analysis. Results are shown in Table IV. 

TABLE IV. FISCHER ASSAYS, MARATHON LEASE SHALE... 

Two shale samples were studied one from the Marathon lease (cores) and the other from the Dow-Colony mine. Clearly, the latter is the more relevant to an ore beneficiation process. 

---