Page 363 - Centrifugal Pumps 2E

328 Centrifugal Pumps: Design and Application

Secondary Oil Recovery (Waterflood)

When no convenient surface water is available, deep well turbine
pumps are used to pump the water containing calcium sulfite to the sur-
face. This is filtered or chemically treated before reinjection to prevent
clogging of the pores in oil sand. The oil and brine mixture then comes to
the surface where it is separated. The water is a corrosive brine with hy-
drogen sulfide from the contact with oil. The brine is chemically treated
and filtered for reinjection or disposed of as waste. Chemical pumps of
316 or nonmetallic can be used to transfer the brine.

Mining—Copper Leaching and Uranium Solvent Extraction
Copper ore is normally less than 1 % copper. Flotation or leaching or
solvent extraction is used to upgrade the ore. Copper emerges as a copper
sulfate and then is pumped to an electrolytic cell where it is plated out.
Pump material, either 316 or nonmetallic, is used at ambient tempera-
ture.
For uranium, a solvent extraction is settled and filtered. The clarified
solution is mixed with kerosene and organic amines. The solution is
stripped and uranium is precipitated as uranium oxide. Nonmetallic
pumps or 316 for low head or ambient temperature are used.

Industrial Waste Treatment
These vary with great quantities due to the nature of the product and
process that they drain. The range of fluids is from a discharge of great
volumes of cooling to small but concentrated baths of inorganic or or-
ganic substances. The pump material is of ductile iron, 316, or nonmetal-
lic. Some of these waste treatments are wastes containing mineral im-
purities, steel pickling, copper bearing wastes (where very small
amounts of copper—less than 1 mg per liter—will interfere with life in a
stream or biological sewage treatment works). Wastes containing chro-
mates or cyanides are used for electroplating and electrolytic operations
where the maximum is less than 1 mg per liter. They are also used for gas
and coke plant wastes, oil-field brines (which are petroleum refinery
wastes, mining wastes, or wastes containing organic impurities). They
are also used for milk processing, meat packing, brewery and distillery,
vegetable and fruit processing, textiles (such as wool, cotton, silk, linen,
and dyes), laundries (which have soap, bleaches, dirt and grease), tanne-
ries, and paper mills (which have black, green, and white liquors). The
pumps could be ductile iron, stainless, alloy 20, titanium, or nonmetal-
lic.