Search Documents

By Albert E. Keller

This paper describing the timekeeping and pay-roll methods of the Britannia raining and Smelting Co. (Ltd.) is one of a series being prepared for and published by the United States Bureau of nines regarding office procedures in connection with mining operations. The general office of the Britannia Mining and Smelting Co. (Ltd.) is located at Britannia Beach, B. C., a town of about 600 inhabitants at tidewater on the east side of Howe Sound and about 30 miles from Vancouver, B. C. The Beach, as it is locally termed, is a company town consisting largely of about 250 employees of the company and their families. Here is the milling and concentrating plant of over 6,000 tons daily capacity- the main service units comprising the electrical, mechanical, blacksmith and woodworking shops and the local electric-furnace foundry; the central-heating steam plant; the air and electric generating units; the ball-manufacturing plant; the warehouses; and the general store, which serves this community and also acts as distributor for the general stores located elsewhere on the property.

Jan 1, 1932

By B L. Sommerville

"The theme of this International Mining Geology Conference is ‘Setting New Standards’. Rio Tinto’s iron ore operations include a complex integrated supply system to deliver ore from 15 mine operations through four independent terminals over 1700 km of rail line. Significant growth in the past 20 years has seen production grow from 88 Mt in 1997 to 329 Mt for the 2016 calendar year.With more than 50 years of mining in the Pilbara, Rio Tinto has extensive experience in developing standardised approaches to mine geology and the geometallurgical prediction of product quality to meet the increasing growth profile and business planning complexity.Rio Tinto’s standardised approach to mine geology can be developed and utilised on a daily basis to enable the optimisation of the supply chain in terms of tonnages and product quality. This experience demonstrates a fully standardised system can balance the needs of a systematic process across all mine sites and the flexibility for mine geologist to determine and use local properties at each mine; this is done by ensuring two key principals are in place: a single, centrally maintained, system is established and maintained, providing a common set of processes and software across all mine sites the system allows senior mine geologists to review and customise key attributes and product regressions, ensuring site specific data is used in product predictions.The benefits of formal work process and standardisation include health, safety and environment, people and skill development, cost and improved communication. Also product predictions from mine geologists are one of the key inputs into an integrated and dynamic mine to ship scheduling system, optimising the supply chain whilst still managing the product quality. The experience of Rio Tinto is that a standardised approach to mine geology is an enabler of value for the iron ore operations.CITATION:Sommerville, B L, 2017. Mine geology standardisation – providing the foundation to consistent short-term geometallurgical product predictions in a complex multimine and supply chain environment, in Proceedings Tenth International Mining Geology Conference 2017, pp 13–20 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 20, 2017

By P. M. Soupios

A near geophysical surface investigation of a landfill area close to the Hania city, in Crete Island, Greece, was conducted as inextricable phase of a preliminary geotechnical, geological and hydrogeological study of the area under investigation. Electrical Resistivity Tomography (ERT), one of the most promising prospecting techniques mainly concerning its effective contribution to resolve several environmental problems, was applied for the geophysical modelling. ERT is a robust imaging method the theory and implementation of which are well documented in geophysical research literature. The survey site is located in Akrotirion Peninsula, about 7km east of Hania city in Crete I. The geological setting comprises Trypalion limestones, marly limestones and a clayed weathered layer. Cavities are also identified at various scales which are recent tectono-karstic voids resulted from the combined actions of karstic erosion and tectonic stress on the Trypalion limestones where they are located. Due to the above-mentioned geological singularity and in the light of the requirement for an environmentally safe construction of the landfill, an ERT survey was carried out by deploying the dipole?dipole electrode configuration. Specifically, seven geoelectrical tomographies were conducted reaching the prospecting depth of 36m. The resulted images conduced, a) to overcome geotechnical problems, b) to plan the future sites for waste disposal and c) to reliably estimate the thickness of the already deposited wastes.

Jan 1, 2005

By M. Ahrens

The paper describes the main drive systems of an iron ore pelletizing plant and related important design aspects. It is shown how today?s drive systems provide the desired flexibility for the process and lead to high energy efficiency and system reliability. With respect to electric drives expansion projects have many technical issues in common with green-field installations. However, there are aspects where important, distinct differences occur. It is shown which considerations for selecting and sizing drive systems for such a plant as well as for integrating them into an overall plant control concept need to be taken into account. Besides the design of the drive systems a key aspect for such an expansion project is the network interaction. Harmonics levels at different points in the plant network need to be checked carefully with simulations during the design phase to avoid problems later-on during operation. The power factor compensation and the harmonic filtering of the new production line cannot be designed independently of the already existing plant. The paper highlights areas where problems could occur and which points need to be paid attention to when a plant is expanded.

Jan 1, 2008

By V. V. Pankov, W. R. Chen, L. R. Zhao

Diffusion nickel aluminide and overlay NiCrAlY coatings were deposited on single crystal Ni-base superalloy CMSX-4 substrate using the chemical vapour deposition and cathodic arc evaporation techniques, respectively. The NiCrAlY coating underwent a post-deposition heat treatment in an argon atmosphere at 1100°C for 2 hours. All the coated specimens were subjected to furnace cyclic oxidation testing at 1000°C up to 1500 one-hour cycles. The morphology, elemental composition and phase constituents of the oxide scales formed on the coating surface were analyzed using scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. It was observed that the diffusion aluminide coating experienced accelerated weight gain at an early stage of the test (150-400 cycles), whereas the overlay NiCrAlY coating fabricated by cathodic arc evaporation maintained steady-state weight gain throughout the entire 1500 cycle test duration. This difference in oxidation behaviour between the two types of coatings is attributed to the early development of nickel-aluminum spinel on the surface of the diffusion aluminide coating, in contrast to the stable aluminum oxide scale formed on the overlay NiCrAlY coating during cyclic oxidation testing.

Jan 1, 2015

By Shawna Von Stockhausen, Hong Yang, Tung T. Vu, Derek Penrice, Kevin Huynh

"The Regional Connector Transit Corridor is a 1.9 mile long light rail transit project in downtown Los Angeles, California. The project includes approximately 4,930 feet of twin bored tunnels together with a mined crossover cavern, 3 deep stations, and other cut-and-cover structures. The bored tunnels will be excavated using an earth pressure balance tunnel boring machine through Fernando Formation (extremely weak to weak rock) and alluvium. The tunneling will be performed in close proximity to a large number of existing structures, including the existing Metro Red Line tunnels with as little as 6 feet of separation. Thus, the evaluations of the tunneling effect on these structures and the instrumentation and monitoring program is an essential part of the project design. This paper provides a very brief overview of the considerations and evaluations of the tunneling effects on the existing structures and results of evaluation obtained during the final design stage of the project. INTRODUCTION The proposed Regional Connector Transit Corridor (RCTC) project provides a 1.9 mile-long connection between the Metro Gold Line from Pasadena and East Los Angeles; and the Metro Blue Line to Long Beach and the Expo Line to Culver City. The alignment is shown in Figure 1. The Regional Connector will provide new tracks through downtown Los Angeles. The project will extend underground from the Metro Blue, Expo, Red, and Purple Lines’ 7th Street/Metro Center Station following Flower Street, curving northeast to the north of 3rd Street under the 2nd Street Tunnel. The alignment will then continue eastward under 2nd Street, turning northeast to cross under the intersection of 1st and Alameda Streets, then splitting into two branches above the ground surface, one branch extending north along Alameda Street and the other extending east along 1st Street. The project elements include 3 deep stations, a SEM cavern, segments of TBM bored tunnels, and cut-and-cover guideway structures. The bored tunnels have an excavated diameter of 20.3 feet. The subsurface conditions along the tunnel alignment generally consist of artificial fill overlaying finer-grained alluvium (dominantly medium dense to dense sandy soils), underlain by coarser-grained alluvium (a wide variety of medium dense to dense sandy and gravely soils). Below the coarser-grained alluvium is Fernando Formation, which is characterized as extremely weak to very weak sedimentary bedrock. A long stretch of the alignment will be excavated in this formation. The soil layers above the Fernando Formation are of variable thickness and spatial distribution. The geologic profile is shown in Figure 2."

Jan 1, 2016

By L. Gutierrez, S. Gering, C. Calderon-Arteaga

"Drill and blast represent the most important, and sometimes the costliest processes in the mine. The cost of drilling and blasting operations greatly contributes to the “high cost trends of the overall mining operations” (Afum and Temeng, 2015). The use of available information to improve the drill and blast processes can be the difference between a wasteful process and one that is optimized for costs, safety and desired fragmentation. Mining operations have access to several types of data sets that include a variety of different systems. This information can be used to improve, evaluate and apply processes for drilling and blasting. This may include different types of data from the different stages of the process (before, during and after the drilling and blasting operations), such as hole locations (planned and actual), penetration rates, drill operators, fragmentation (expected and resulting), explosive (design and usage), geology, vibration and others. This information can be used on its own or combined for further analysis to reduce costs, improve safety and evaluate results. Fortunately, due to advances in mining software, drill and blast engineers can exploit this data and create reports to evaluate results and improve the drill and blast process. However, as users start combining information from multiple datasets and establishing standard operating procedures for reporting across multiple sites, it becomes valuable to create auditable, automated and sustainable workflows for handling the information.In some cases, the task of aggregating and standardizing the data formats has already been completed and is available to consumers via the Enterprise Data Warehouse (EDW). A data warehouse team extracts data from the source systems and transforms it so that it is meaningful for decision support (Wixom, Watson, 2007). The author’s initial implementation plan for the drill and blast solution included using data stored at the sites on local servers. However, we learned early in the process that much of the work for aggregating and supplying the required data was already completed and was available in the EDW ready for use. This saved time, reduced risk and added value to the system.The goal for this case study is two-fold: to show how information can be used to make decisions and improve processes, especially highlighting the value of using an EDW for managing drill blast information; and to discuss how technical challenges encountered during the implementations were resolved. This article targets users that want to better manage their drill and blast data or try to set up standardized workflows for using this information.This case study will discuss the process of implementing a drill-and-blast workflow at multiple sites within Freeport-McMoRan (FMI) using both data at the sites and information available from the EDW."

Jan 5, 2017

By E. J. HOFFMAN, J. c. W. FRAZER

The apparatus and methods described in the following pages were devised and used by the writers in connection with certain investiga- tions of the technologic branch of the United States Geological Sur- vey, especially those bearing on the improvement of furnace condi- tions and on efficiency in the use of fuel. The Bureau of Mines, which has charge of such analyses and tests of fuels as were formerly made by the technologic branch of the Sur- vey, is using the same apparatus and methods in connection with similar investigations that are being carried on at the testing plant of the bureau at Pittsburg, Pa. The furnace conditions prevailing both in small plants and in large industrial establishments in this country are frequently far from satisfactory. If such conditions are to be improved, they must be more thoroughly understood, and means must be found to insure complete combustion of the fuel, and yet to permit operation with such an excess of air as will result in the greatest efficiency. In this work the services of the chemist are indispensable. A very important problem is the determination of the small percentage of unburned combustible matter that escapes from the furnace in the flue gases. Under ordinary circumstances so little as 0.1 per cent of unburned combustible matter in a furnace gas is equivalent to about 1 per cent of the fuel used; and for the determination of such small percentages of gas more accurate and refined methods are required than have ordinarily been available heretofore. It is the purpose of this paper to describe some apparatus and methods which have proved satisfactory to those engaged in the chemical work of the investigations mentioned. While these methods and apparatus have been designed more particularly with regard to analysis of furnace gases, their use is by no means limited to that purpose. The reader will readily see their applicability to other uses in which the sampling and analysis of gases are involved.

Jan 1, 1911

Commodities statistics and otter information are available through the following t et systems: Internet Access: To acccess the USBM Gopher server on Internet, connect to: gopher.usbm.gov port 70, using gopher client software. Or contact the Systems Administrator for technical questions: Matt Klevemann, 412-892-6499 (klevemmc@miner.usbm.gov) These USBM materials are available on Internet, with more to come in the future: Publications and other research findings, including this bimonthly publications list, newsletters, tech transfer updates, enviromental technology research, health and safety information. USBM software products Media materials and speeches. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. Mines FaxBack: Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219-3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button on your fax machine.

Jan 1, 1995

By A. Yousefpour, M. Hojjati, M. Simard, M. Laramée, M-A. Octeau

The need for effective and reliable joining methods grows as the use of advanced thermoplastic composites becomes widespread in aerospace industry. An experimental investigation of resistance welding of APC-2/AS4 thermoplastic composite laminates is presented. In this method, a heating element is placed between the bond-surfaces then the interface is heated by passing electrical current through the heating element. The polymer at the weld interface is melted due to resistance heating, then diffuses and consolidates under applied pressure, resulting in a weld. APC-2/AS4 prepreg, APC-2/AS4 commingled, and different grades of metal mesh heating elements were considered. A custom made resistance welding rig was designed and developed to perform lap-shear welds. The mechanical performance of the welds was quantified using single lap shear tests. The effects of different heating elements on the mechanical performance of the resistance-welded parts were investigated. Also, quality of the welds was examined under optical microscopy.

Jan 1, 2004

By T. Shellhammer, A. Park

Among all pure metals, copper has the second highest thermal and electrical conductivity, next to silver. These properties coupled with a reasonable cost, make copper ideal for use in metallurgical vessels as a conductor of electrical current, as well as a lining material and protector of refractories and steel superstructures. Treatments of copper to address it’s softness and low melting point, specifically hard surfacing and calorizing, will be discussed. This paper will cover the evolution of copper to its current form, offer comparisons to other materials, and theoretical and empirical evidence on its superior performance in metallurgical vessels such as blast furnaces, basic oxygen converters and electric arc furnaces. Some case studies will be provided and finally a brief summary.

Jan 1, 2015

By Francis Martino

There are numerous techniques and predictive models used by geologists and mining engineers to define coal reserves and plan mines. The traditional reserve estimation methods commonly used include the isopach, triangular, polygonal, inverse-distance weighting, weighted-moving-average, and trend-surface methods. Geostatistically-based estimation techniques are now being examined by many geologists and mine planners as a superior alternative to these traditional methods. With today's coal mine development costs often exceeding $100 million, and power generation $1 billion, it is logical that a technique that can indicate the degree of confidence associated with a reserve estimate (fuel supply), and thus also the degree of risk, is highly desirable to the coal producer, the financiers, and those desiring to commit to coal utilization under short or long-term supply arrangements.

Jan 1, 1983

By C. C. Pretorius, S. Ramjee, R. J. Mostert

The study investigates the effect of prior corrosive exposure on crack growth resistance behaviour of thin sheet (3 mm thick) aluminium alloy 2024-T3 at slow strain rates. Compact tension specimens were exposed to standard corrosive environments that simulate accelerated atmospheric corrosion attack. Two corrosive environments were considered – an exfoliation corrosion (EXCO) solution and a 3.5 wt% sodium chloride solution. The unloading compliance R-curves of the two-hour EXCO-exposed specimens revealed a significant degradation of approximately 11% in the crack growth resistance behaviour (Kc_e values) compared to the baseline (air-exposed) values. Furthermore, secondary intergranular crack formation was also revealed in the plastic zone ahead of, and adjacent to, the crack tip of these specimens; which formed during the crack growth resistance loading. It is postulated that the observed degradation of the Kc_e values of the EXCO-exposed material is due to hydrogen embrittlement since the exposure times for the EXCO evaluation were limited to ensure that uniform corrosion dominated; that is, significant penetration of corrosion damage and pitting due to localized corrosive attack did not occur. The sodium chloride-exposed specimens revealed a similar degradation (13%) after 24 hours exposure. However, slight intergranular corrosive attack and isolated pitting were observed on the exposed surfaces prior to crack growth resistance loading, resulting in notch effects that could assist in crack growth. Pitting and intergranular corrosion were, however, not observed at the pre-crack tip. The relative contributions of the notch effects and the hydrogen embrittlement during the degradation of the KR performance are, therefore, unclear.

Apr 1, 2021

By D. T. Kirkwood

The practice of impounding mine water and liquid fine waste in underground mines is increasing. Often these underground impoundments are created by constructing seals or bulkheads designed to withstand the expected hydraulic pressures. Occasionally seals are built for another purpose, usually to act as explosion-resistant ventilation barriers. Due to factors such as clogged drain pipes or unexpectedly high inflow rates, these explosion-resistant seals sometimes become subjected to hydraulic pressures. The incidence of seal failures due to inadequate design and/or construction is also on the increase. Fortunately, to date, no lives have been lost by water seal failures, but a clearer understanding of the design and construction considerations specific to water seals is vital to keep this from occurring in the future. This paper presents technical considerations for the design and construction of seals which will specifically be required to withstand hydraulic pressures in underground mines.

Jan 1, 1995

By Gurubasayya Swamy

This paper presents the consequences of modernization and expansion of process plant by implementing SAG and Ball Mill and Carbon-in-pulp technology at the Hutti Gold Mine. From the inception of the process plant, it has undergone many changes for the improvement. In the beginning, only gravity recovery of gold was carried out by using Pebble Mills and Strake Tables. Later amalgamation, Cyanidation and Zinc precipitation and finally Carbon-in-pulp gold recovery system was implemented. Grinding plant was modernized by implementing SAG and Ball Mill and Knelson concentrator for free gold recovery as a result, the production rate, rate of recovery, reduced man power, Modernization and expansion of process plant has also yielded in safe and smooth running of the plant. Keywords: sag and ball mill, cip, modernization and expansion, productivity, gold recovery

Sep 1, 2012

By Jerome P. Downey

In the thermal treatment of electric arc furnace (EAF) dusts, zinc is reduced, volatilized, and ultimately recovered either as liquid metal in a splash condenser or as solid zinc oxide in bag filters. During the process, the duet's chlorine and fluorine content also enters the gas phase and condenses as dross in the splash condenser or as salts which contaminate the zinc oxide product. Pretreatment of EAF dust by pyrohydrolysis appeared to offer a means of minimizing the duet's halogen content. The primary research objectives were to experimentally verify the technical viability of pyrohydrolysis and delineate the process parameters requisite for efficient halogen removal. To this end, representative EAF duet samples were secured and characterized by x-ray diffraction, scanning electron microscopy, and Mössbauer analyses. Specific- experimentation focused on the response of halogen extraction to variations in temperature, retention time, water vapor partial pressure, and various additives. The experimental results proved that 97 to 99 percent chlorine extraction and 80 to 85 percent fluorine extraction are consistently achieved when EAF dusts are blended with silica and roasted at temperatures of 850°C or greater in a furnace atmosphere of 75% steam (diluted by air). A statistical analysis further established that more than- a single optimal point exists, thus affording flexibility in parameter selection (e.g., by increasing temperature, the necessary retention time and additive concentrations are decreased). The findings substantiate the feasibility of pyrohydrolysis roasting in reducing the chlorine and fluorine in the EAF dust to a level that will obviate industrial concerns about halogen contamination. The end-product of the pyrohydrolysis procedure is a de-halogenated, self-fluxing calcine which can be directly charged to a plasma or flame reactor. The paper includes design parameters and flow diagrams illustrating the pyrohydrolysis process integrated with the plasma and flame reactor technologies.

Jan 1, 1992

By Joshua Farmer, Mike Gianforte, Tao Jiang, William Gettings

The Two Rivers Water Reclamation Authority (TRWRA) in Monmouth County, New Jersey, is replacing its aging Pleasure Bay Interceptor (PBI) with a new 54-in interceptor in a 3,250-foot long 8 to 10-foot diameter tunnel and a new 50-mgd main pump station (MPS). A comprehensive phased geotechnical investigation was performed, including SPTs, CPTs and geophysics. A channel filled with soft marine sediments was identified. The tunnel is set in stiff to hard marine soil to enable using a less expensive open-face TBM. The thickness of tunnel cover under the channel is optimized through numerical analyses to avoid a deeper pump station yet maintaining tunnel stability with controlling seepage.

Jun 13, 2021

By Gerard C. Gambs

The electric utility industry is the largest customer of the U.S. coal industry, consuming nearly 50% of present coal production. By 1980, the electric utilities are expected to burn over 500 million tpy of coal or 75% of total coal production. When coal is burned in electric utility plants, ash is produced in one of several forms. These include fly ash, bottom ash and bottom slag. At the present time, approximately 20 million tons of these ashes are produced and must be disposed of by the utilities at a cost of 50[c] to $2 per ton. In 15 years, more than double this quantity will be produced. Only a small quantity of this ash is put to any practical use. Much remains to be done about expanding uses for fly ash and bottom slag.

Jan 1, 1967

By G. B. Atkinson

The Bureau of Mines investigated a method for increasing the leaching rate of bulk superalloy scrap to facilitate recycling and recovery of critical metals such as Ni, Co, and Cr. Three superalloys were investi- gated, the cast-nickel-base superalloy IN-738, the wrought-nickel-base superalloy Rene-41, and the cast-cobalt-base superalloy Mar-M-509. Superalloys melted with 20, 30, 40, and 50 pct Al metal to form inter- metallic compounds were easily crushed to a convenient particle size and reacted rapidly with acid solutions which dissolved the metals. For example, leaching 1/2-in pieces of unalloyed IN-738 with excess 6N HC1 at 95° C for 2 h dissolved about 0.5 pct, while leaching 10 g of minus 20-mesh 30 pct Al-70 pct IN-738 with excess 6N HC1 at 95° C for 2 h dis- solved 96.2 pct.

Jan 1, 1983

By John N. Dew, William L. Martin, `

This paper describes the results of a laboratory investigation conducted to obtain data for an evaluation of the in situ combustion process as a method of producing crude oil from reservoirs. Air and fuel requirements, rates of advance, com-bustion temperatures, and coke and fluid distributions are presented. The mechanism of oil recovery by in stiu combustion is discussed. Five crude oils ranging in gravity from 10.9 to 34.2"' API were prodrrced from a semiadiabatic, uncon-.solidnted sand pack by in situ combustion. Experimental conditions were varied over a wide range in order to determine the inter-relation-.ships of process variables. The mini-mum air flux requirement for self-sustained combustion was found to he less than 10 scf/hr-ft'l. The rate of advance of a self-sustained combustion zone was found to be nearly proportional to the air flux at the combustion front. The effects of presrure and injected air flux were studied in a series of experiments using a 21.2" API crude. A minimum air require-ment was observed at an air .flux of 20 scf/hr-ft'. The oil saturation con-sumed as fuel averaged 5.5 per cent of pore volume. The effect of air pressure was, found to be .small for experiments having high combustion eficiencies. This study should promote a better understanding of the problems and mechanisms involved in labora-tory investigations and field applications of the in situ combustion pro-cess. The data presented will be use- ful in the interpretation of results of field tests. When tempered with volu-metric sweep efficiencies, the data can be used in making preliminary economic appraisals of the process as applied to reservoirs containing high porosity unconsolidated media. INTRODUCTION The purpose of this work was to obtain laboratory data for an evaluation of the in situ combustion process as a method of producing crude oil from reservoirs. In situ combustion basically consists of (1) injecting air into a reservoir through selected input wells to create an air sweep through the reservoir, (2) igniting the crude at the injection well, and (3) propagating the combustion front through the reservoir by continued air injection. By this means, oil is swept toward producing wells in the area. The fuel for combustion is supplied by heavy residual material (coke) which has been deposited on the sand grains during distillation and cracking of the crude oil ahead of the combustion front. Recovery of petroleum by a combustion or heat wave process is not a new idea. F. A. Howard was granted a patent in 1923 on a process in which air and a combustible gas were pumped into an injection well and ignited.' Russian engineers reported on field experiments with a crude oil gasification process in 1935'. Other known early field tests include those conducted near Bar-tlesville and Ardmore, Okla., in 1942." More recently completed field tests include an inverted seven-spot by Sinclair Oil Co. in the Delaware-Childers field, Nowata County, Okla.'; a three-well and an inverted five-spot test by Magnolia Petroleum Co. in Jefferson County, Okla."."; and a test by California Research Corp. in the Irvine-Furnace field in Kentucky. The Worthington Corp. has completed a test in cooperation with the Forest Oil Corp. in Clark County, 111.l Several field tests are now in progress. Sinclair has acquired a 600-acre lease in the Humboldt-Chanute field, Allen County, Kans., and is under way with a large-scale operation. Three field tests are under way in California. The General Petroleum Corp. is conducting an inverted five-spot pattern test in the South Bel-ridge field in Kern County under a cooperative agreement with 11 other companies, including Continental Oil Co. California Research Corp. is conducting a four-well pattern test in Midway-Sunset field near Maricopa, and Richfield Oil Corp. is under way with a test in the Ojai field in Ventura County. Although the published information is valuable concerning results of field tests, little laboratory data other than that reported by Kuhn and Koch5 are available to aid in appraising the tests from a technical or economic standpoint. Engineering data needed to evaluate the process include the amount of air required per barrel of oil recovered, minimum injection rates which will support combustion, rates of advance, air required per unit volume of reservoir cleaned, amount of oil recovered, and amount of oil consumed as fuel. The present laboratory investigation was undertaken to provide these data for that portion of the reservoir swept by the combustion zone. The first phase of this investigation was exploratory in nature and was conducted at injection pressures less than 100 psig. Data were ob-