Metallurgy Laboratory Equipment

The Hammond Mining and Metallurgical Laboratory and its Equipment was the gift of Prof. John Hays Hammond to the Sheffield Scientific School of Yale University. Professor Hammond was graduated from this school in the class, and has always shown great interest in its welfare and progress. He offered to build and equip for it a mining and metallurgical laboratory. This offer was gratefully accepted by the trustees; and in October of the same year the architect, W. Gedney Beatty, and I were employed to draw up plans for the building, which is the largest of its kind in this country.

The Treasurer’s report shows the total gift of Professor Hammond, including land, building, and equipment, to have been $1,228,741. This does not include $5,000 given by Professor Hammond to defray incidental expenses. The detailed cost of the machinery and installation, included in the above sum, is as follows:

Requirements of the Metallurgical Laboratory

Before planning the building, the mining-laboratories and ore-testing plants in the East were visited, and blueprints of the Western and Canadian mining-laboratories were studied carefully. The methods of instruction and laboratory-work required of the students at different mining-schools were also carefully compared. After the completion of this preliminary work it was found that the equipment and laboratory-work required were different in the several universities, and that the design and equipment of the Hammond Laboratory would depend entirely upon the requirements placed upon it. A consultation with Professor Hammond resulted in the decision to erect a building to fulfill four requirements:

1. Teaching of the theory and practice of assaying, metallurgy, mining, and ore-dressing.
2. Testing of ores on a small scale to determine the most economical method of treatment.
3. Handling of ores on a commercial scale in order to verify the results obtained from the preliminary testing.
4. Research-work and investigations by the instructors or by professional men to develop new processes or perfect new machines.

The first requirement called for lecture-rooms and lecture-tables fitted with gas, water, and electric power for classroom experiments; also a museum for mining- and metallurgical models and the products of mills and smelters.

The second requirement, space for small ore-testing machinery.

The third requirement, space for full-sized machines, and floor-space for the installation of new machinery without changing the proposed arrangement.

The fourth requirement, and the most important for the advancement of the profession, space equipped with power, gas, and water for investigations on a large or small scale.

Erection of the Building

The building was designed with the above objects in view, and the plans were accepted in May, 1904. The building-contract called for the building, and the furnishings for the library, lecture- and research-rooms, and also the desk-rooms for assaying and ore-testing. Ground was broken in June, 1904, and the building was ready for occupancy in November, 1905. During the autumn and winter of 1905 the assay-furnaces and small ore-testing machines were installed, and the supplies for the department of assaying were purchased. The first course in assaying and ore-testing was given the following spring. While this work was in progress, museum-cases and the balance of the furnishings were designed and built, and plans were drawn for the arrangement of the ore-dressing machinery, the order for which was placed on July 1,1906, with the Allis-Chalmers Co. The first delivery of machinery was made in October, 1906, and in January, 1907, the first rock was broken in the crushing-room. In June the mill-wright, A. A. Watson, completed his work, and the first ore was milled during that month.

The building has a frontage of 84 ft. on Mansfield Street, and a depth of about 200 ft., extending back to the Northampton Division of the N. Y., N. H. & H. R. R. The detailed dimensions of the various rooms can be derived from the plan, Fig. 1. The lot upon which it is placed has a frontage of 100 ft. The railroad company built a siding at the rear of the building for the delivery of ores.

The building is constructed of fire-proof materials throughout, consisting of granite, limestone, brick, concrete, and steel. All exterior walls are lined with hollow brick, which was coated, before plastering, with anti-hydrene. The ground floor of the entire building is of cement, 5 in. thick. All steam-, gas-, water-, and electric conduits are exposed. The roof of the building, consisting of terra-cotta book-tile covered with slate, is supported by heavy iron trusses.

Description of the Building

Floor-plans and sections of the Hammond Mining and Metallurgical Laboratory are given in Fig. 1, which shows also the arrangement of the different pieces of apparatus.

The ground floor of the building is divided into three portions. The front portion consists of a basement and two floors. The floors, built of steel, hollow brick, and concrete, are divided into various rooms by partition-walls of hollow brick. The stairs connecting the floors are of steel with slate steps.

The second or laboratory portion of the building, adjoining the front portion, was designed to furnish as much light and air as possible, allowing for an increased floor-area. The side-walls are 27 ft. high, and the roof in the center of the building is 44 ft. high. In the center of the roof, for ventilation, there are monitors with sash windows on each side, which are opened and closed by gearing and chains extending to the floor. The windows in the side-walls are 5 ft. apart and are 20 ft. high by 5 ft. wide. These windows are divided in the center for the building of mezzanine floors along the outside walls as soon as the increased floor-area is required. Around the windows are steam-coils for heating, and from the roof-trusses are suspended arc-lamps for lighting. Between the windows and every few feet along the transverse walls are incandescent-lamp outlets, to which lamps can be attached to provide light for inspecting the machines.

This portion of the building is subdivided by two transverse walls into three rooms, having a total floor-area of about 12,000 sq. ft., which can be increased 10,000 sq. ft. by building the mezzanine floors planned. Eight chimneys were built in the transverse walls, two of which are lined with fire-brick. The floor of the large room slopes to a central sump, 12 ft. square by 3 ft. deep, with 12-in concrete sides and bottom. The floor of the sump slopes to a depression in one corner, which has a connection with the sewer, controlled by a gate-valve. In order to prevent the seepage of water into the sand under the building, the sump was lined with several layers of tarred paper and felt, held together with hot tar and covered with cement. The sump is connected with the main water-supply, and a pump is provided to enable the water to be used to supply the tank on the top floor. The floors in the other rooms are horizontal, with the exception of the space devoted to ore-testing, which slopes to open drains. In buildings of this character it would be better to have all the concrete laboratory-floors slope to an open drain for convenience in washing. Some of the concrete floors have been painted and others oiled to prevent dust from the surface-wear of the concrete. Both methods have proved satisfactory. The paint gives a much better appearance but requires repainting, whereas the oil shows no wear.

The third portion of the building is triangular, conforming to the shape of the lot. It is divided into an upper and a lower floor: the former, a crushing-room; the latter, a boiler-room for steam-heating and a repair-shop.

Library, Museum, Etc.—The front portion of the building is devoted to the library, museum, lecture-rooms, and research-rooms. The first floor contains the library, museum, and office.

The library, to the left of the hall, has two windows facing east and two facing south. The room is furnished with shelves and two large tables, lighted by individual electric lamps and a ceiling-cluster.

The museum, across the hall from the library, has six windows. This room contains museum-cases and chests of drawers for student collections. It is intended to place in the museum typical flow-sheets of mills, and in the cases and drawers the various products from these mills. This arrangement will assist the student in studying the practical handling of ores from various districts. Here also will be placed models and photographs of mining-, metallurgical, and milling-plants and machinery.

The office is connected with the library and the hall.

Between the office and the museum and directly in front of the entrance are a hall-closet and an office-closet. Ultimately these closets will be used as a hallway connecting the entrance-hall with the mezzanine floors to be built later in the second or laboratory portion of the building as soon as this extra space is required.

On the second floor are two lecture-rooms, an instructor’s room, and a hall-closet. Both lecture-rooms are furnished with chairs on stepped floors, lecture-tables fitted with gas-, water-, and electric-light connections, and an electric switch for power. The rooms are ventilated through a grating in the ceiling, which connects with a skylight in the hall-closet.

The large lecture-room can accommodate 112 students. The lecture-table, 18 ft. long, contains large flat drawers for charts and maps. Back of the lecture-table are eight museum- cases with closets below. The four central cases have sashes of slate for blackboard-work; the four outside cases have sashes of glass. There are also two connections for a lantern, one at the side of the lecture-table, the other in the rear of the room.

The small lecture-room can accommodate 45 students.

The instructor’s room at present contains an electric blue-print frame and drawing-tables.

The basement, on the ground floor of the building, is subdivided into research-rooms, supply-rooms, locker-rooms, shower- baths, and lavatories, all heated by steam-coils suspended from the ceiling, and lighted by ceiling-clusters.

The two corner rooms are devoted to research-work. These rooms are furnished with desks, hoods, and electric power-plugs for power or electric-furnace work. Each room is lighted by three windows, individual electric lights on the desks, ceiling-clusters, and extra light-outlets in the walls for special work. The desks are equipped with water, gas, and electricity.

Adjacent to the southeast research-room is an instructor’s room, equipped with desks for use in assaying. This room connects with the central hall and the assay-laboratory. The students’ samples for assaying are stored in this room, together with the assay-records.

Adjacent to the northeast research-room is the balance-room, connecting with the assay-laboratory. This room is equipped with nine Becker button-balances, two Keller button-balances, and one Becker analytical balance. Light is furnished by one window, and each balance has an individual electric light.
The supply-rooms and dark-rooms are interior rooms connecting with the central hall. The supply-rooms contain shelves and drawers. The dark-room is furnished with a slate desk, water, gas, electric lights, and an exhaust-fan for ventilation.

The students’ locker-room, for changing clothes, is in the front of the building, connecting with the central hall. This room can accommodate 80 lockers, 56 of which have been already built. Connected with the locker-room are two shower-baths and a lavatory.

The instructors’ lavatory, containing lockers and a shower, connects with the hall, and is adjacent to the southeast research-room. Hot water is supplied to the showers from a Rudd automatic gas water-heater.

Ore-Testing Laboratory Equipment

The first laboratory room, entered from the basement hall, is devoted to ore-testing and assaying. On the south side of the room, the equipment for ore-testing consists of eight working-tables covered with linoleum, and furnished with open drains to the floor. Above the tables are water-pipes furnished with dial plug-cocks leading from a reservoir on the wall, whereby a constant pressure is maintained. Adjacent to the windows are one gas drier and two steam driers. The apparatus installed consists of five Vezin jigs, five glass classifiers, three Munroe tables, sizing-screens, gold-washing and amalgamating-pans, bateas, and accessories necessary for the testing of ores.

Assay and Metallurgical Laboratory Equipment

On the north side of the first laboratory-room, 18 assay-desks were installed when the building was completed, and last summer 24 more, making a total of 42. The original desks were covered with slate and contained lockers, drawers, shelves, and desk-lockers for pulp- balances. The desks installed last summer differ by the addition of a cupel-drawer and the omission of the balance-locker. This arrangement reduces the number of balances required by one-half, and also gives the student a tray for cupels which otherwise would have to be kept in the locker below. The desks are placed in six sections; the three new sections contain eight desks each, and the three original ones contain six desks each, with three deep slate sinks at the ends. The desks have individual electric lights, are supplied with gas, and are subdivided to accommodate 84 students in two divisions. Distilled water is supplied from bottles supported on the top shelves. To prevent the stoppage of the sink-drains by ores from the preliminary vanning, and to prevent the destruction of the waste-pipes by acids, a 2-in. overflow is placed in each discharge-pipe, and the bottom of the sink is covered with broken limestone. The balance of the equipment in the desk-room consists of a hood, pulp-balances with individual sets of weights, and the general supplies required by an assayer. The students are charged, at cost, with a complete outfit for assaying, including weights, crucibles, etc., and at the end of the term the supplies not used and in good condition are returnable and full credit is

Rooms and Apparatus of the Hammond Mining and Metallurgical Laboratory given. The laboratory fee, which covers reagents and coal.

The second laboratory, adjacent to the first on the west, known as the furnace-room, has an available floor-area of 2,300 sq. ft., with a passageway of 10 ft. in the middle. As originally planned, this room was to have been devoted to assaying and metallurgy, but it has been found that the entire space will have to be devoted to assaying. The furnaces for metallurgical work, when built, will be installed on the proposed mezzanine floor, which will likewise have an area of 2,300 sq. ft. The two west windows in this room are door-windows, through which the soft coal is delivered to the steel coal-bin for the assay-furnaces. The bin is 8 ft. wide, 80 ft. long and 5 ft. high. Eight soft-coal, double-muffle assay-furnaces are installed 5 ft. in front of the coal-bin. Built of brick and lined with standard linings purchased from the Fire Clay Co., these furnaces are similar to those used in the large mining- and metallurgical works in the West. Each furnace has its equipment of tools for firing and muffle-work. The students fire their own furnaces, and are responsible for the furnaces assigned to them. Facing the soft-coal furnaces are five muffle-furnaces, built by the American Gas Furnace Co., and two crucible coke-furnaces. The gas-furnaces were purchased through, and erected free of charge by, the New Haven Gas Co. The crucible-furnaces were designed and built in the laboratory. Air is supplied to the gas-furnaces by a Roots rotary blower operated by a variable-speed motor. This blower is of sufficient size to furnish air to 12 gas assay-furnaces or to a small cupola-furnace. The balance of the equipment consists of tables, pouring-molds, anvils, and the tools necessary for furnace-work. The floor-area in this room can accommodate 27 soft-coal, 8 gas-, and 2 crucible-furnaces. If gas-, gasoline-, oil-or crucible- furnaces are used in preference to the soft-coal furnaces, a much larger number can be installed. Soft-coal furnaces are preferable for student-work, since they are used at large mines and metallurgical works. When the equipment is increased, a few gasoline-furnaces will probably be added in order that the students may become familiar with the operation of this type of furnace.

Milling Laboratory Equipment

The large room in the rear of the building, adjacent to the furnace-room, contains the concentrating- machinery. It has a central sump with the entire floor sloping to it. The concentrating-machinery is situated between the sump and the west wall. The cyanide-plant and five small amalgamating-pans are adjacent to the south wall. The remaining floor-area is reserved for new machines, dry-concentrators, and magnetic separators. To secure the desired fall for the ore, it was necessary to erect three floors adjacent to the west wall. These floors will not interfere with the mezzanine floors to be built later on both sides of the room. The concentrating-machines were placed on separate concrete foundations extending 2 ft. below the ground floor and from 6 to 12 in. above the floor, depending on the machine. The stamp-mill foundation is a block of concrete, 8 by 14 ft. and 6 ft. deep, with a mortar-block of concrete, 5.5 ft. high. The machines are so arranged as to make their sequence interchangeable. The concentrating-machines on the main floor can be connected with centrifugal pumps, allowing the products to be sent to any other machine or to de-watering-cones placed on the top floor, the products of which, in turn, can be fed to classifiers or to any part of the room. The machinery can be operated for the testing of ores in car-load lots, or a small amount of ore can be circulated over one machine, allowing the student to study its adjustments.

The arrangement of the machinery installed is as follows : In the center of the room adjacent to the west wall is a platform- elevator for elevating ores to the various floors and the crushing- room. The five-stamp battery, with stamps each of 500 lb. and amalgamating-plates, is placed directly in front of the elevator. The battery can be fed either by a Challenge feeder or by hand. The pulp from the plates discharges to an amalgam-trap, and can then be fed to a centrifugal pump discharging to any machine or to de-watering-pans, the water being returned to the sump. To the left of the stamp-mill are the concentrating-tables, consisting of a Wilfley table and a slimer, both donated by the Mine & Smelter Co., and a Frue vanner. The products from the tables can be fed to one of two centrifugal pumps placed adjacent to the tables, or to de-watering-pans. To the right of the stamp-mill are placed a Huntington mill, jigs, an amalgamating-pan, and a clean-up pan. The Huntington mill is 3.5 ft. in diameter, with an apron-plate for amalgamation. The pulp from the Huntington mill can be fed to a fourth centrifugal pump or to de-watering-pans. The jigs, of the Harz type, one of three and one of five compartments, 18 by 24 in., were designed and constructed in the building. They are elevated above the floor-level, allowing the products to be drawn off into de-watering-pans or to go directly to a centrifugal pump. The amalgamating-pan and clean-up pan are placed directly back of the jigs.

The first floor, at an elevation of 12 ft. above the ground floor, contains three Brown hydrometric classifiers. This floor is also the feeding-floor to the Challenge feeder preceding the stamp-mill. The second floor, at an elevation of 20 ft., contains three de-watering-cones. Between the second and third floors are a Challenge feeder, a Vezin sampler and three sets of trommels. The water-tank supplying the mill is on the top floor, and receives its supply of water from either the sump or the city supply.

The cyanide-plant consists of two solution-tanks, three ore-tanks, two 3-compartment precipitating-boxes, two sump-tanks, and a centrifugal pump connecting the sump-tanks with the solution-tanks. One of the ore-tanks is equipped with mechanical stirrers, and a second tank can be connected with a centrifugal pump for agitation. A Johnson filter-press, donated to the laboratory by the manufacturers, the John Johnson Co., is adjacent to the cyanide-plant. On the platform containing the precipitating-boxes are two Harz jigs, one of three and one of five compartments 9 by 9 in. Adjacent to the cyanide-plant are five small amalgamating-pans for the testing of ores. The remainder of the equipment consists of motors, four large steam driers, one gas drier, and ore-bins. Six centrifugal pumps are used: four for elevating ores, one with the cyanide-plant, and one to supply the water-tank. Water- and gas-pipes, fitted with plugs every few feet, extend along both outside walls. In three corners of the room are electric switches for power. The concentrating-machinery is driven from a main line of shafting belted to a 35-h.p. motor. The cyanide-plant and amalgamating-pans are operated in like manner by a 5-h.p. motor. The ore-bins are adjacent to the west wall back of the concentrating-machinery. It is intended to store car-loads of ore on the narrow strip of land south of the building.

Crushing Room, Boiler-Room

The crushing-room has a floor-area of 950 sq. ft. which may be extended to the north, giving a total area of 1,500 sq. ft. The heavy machinery along the interior wall consists of a Blake breaker, 10 by 7 in., tight-and-loose pulleys, driven from main line of shafting; a Gates gyratory breaker, size No. 0, style D, friction-clutch on breaker, driven from main line of shafting; a Dodge breaker, 4 by 6 in., tight-and-loose pulleys, driven from main line of shafting; crushing-rolls, 12 by 12 in., belt-driven from short shaft connected to main line of shafting by friction-clutch; an Abbe pebble-mill, 30 by 19 in., tight-and-loose pulleys, driven from countershaft; a Krupp ball-mill, tight-and-loose pulleys, driven from countershaft. The two machines last mentioned were gifts of the Abbe Engineering Co. and Thos. Prosser & Sons. The machinery along the exterior walls consists of a sample-grinder, coffee-mill pattern, tight-and-loose pulleys, driven from countershaft; a Case laboratory-breaker, a jar-mill, and a power bucking-board, all driven from second counter-shaft; a shaking-screen, with an adjustable stroke, speed, and inclination, driven from a double-cone friction-pulley. The remainder of the equipment consists of various samplers, screens, bucking-boards, and supplies necessary for the breaking, crushing, and sampling of ores. The main line of shafting is driven by a 15-h.p. motor.

Below the crushing-room the floor-space is subdivided into a repair-shop, a boiler-room, and a coal-bin. The repair-shop, triangular in shape, contains the general switch-board supplying the building with electricity. An electric switch provides the current for operating a 5-h.p. motor in the northeast corner. The room is lighted by three windows and ceiling-clusters. It is intended to install in this room a lathe, drill-press, and other machines for repairs and construction as required.

The boiler-room contains two boilers for heating the building with steam. This room is lighted by three windows and electric lights. In the ceiling is an opening to permit the radiated heat from the boilers to enter the crushing-room.

In the northwest corner is the coal-storage, with windows on the railroad-siding and yard. It is of sufficient size to hold a car-load.

Floor-Areas

The total floor-area in the building amounts to 22,871 sq. ft.; the front portion contains 6,691 sq. ft. and the laboratory portion 16,180 sq. ft. By the building of the mezzanine floors, planned in the original design of the building, this floor-area can be increased by 10,750 sq. ft., making a total available area of 33,621 sq. feet. The subdivisions of the area are as follows: