US2221620A - Copper smelting - Google Patents

Description

Patented Nov. 12, 1940 COPPER SMELTING Richard A. Wagstaff, salt Lake city, Utah, as,

signor to American Smelting and Refining Uompany, New York, N. Y.a corporation of New Jersey Application October 10, 1939, Serial No. 298,738

3 Claims.

This invention relates to the smelting of copper ores and provides certain improvements in the construction of smelting furnaces of the reverberatory type and in the conduct of the smelting operation.

Among other features, the invention provides a deep bath smelting process wherein the liquid matte and slag freely iiow from the smelting zone into a settling zone while automatically 10 excluding unfused charge from the latter.

Various other features and advantages of the invention will be apparent from the following particular description taken in connection with the accompanying drawings forming a part 15 thereof, in which:

Fig. 1 is a sectional plan view of a reverberatory furnace for practising the invention;

Fig. 2 is a longitudinal section through the furnace shown in Fig. 1; and

20 Fig. 3 is an enlarged cross-section taken at the line 3-3 of Fig. 2.

Like reference characters denote like parts in the several figures of the drawings.

Referring to the drawings more in detail, there 25 is shown a reverberatory furnace interiorly divided by a dam or baiiie wall I into a smelting zone I 2 and a settling zone I4.A Communication between the two zones is provided by the plurality of passageways I6 and I8 in the wall The smelting section of the furnace is shown as comprising arch 20, side walls 22, flue off-take 24, burner openings 2B in end bridge wall 28 for burners 30, converter slag launder 32 and a silica 35 floor 34 overlying slag bottom 36. The settling section, which will ordinarily be from about onethird to one-half the length of the smelting section, is shown as comprising arch 38, side walls 4D, end wall 42 with burner port 44, slag tap 46 40 and matte tap 48.

A pair of feeders 59, of the type shown in United States Patent Nos. 1,822,944 and 2,037,- 554 granted September 15, 1931, and April 14, 1936, respectively, to Richard A. Wagstaff, are

45 so mounted that they can be projected into the smelting zone and supply the charge to the bath at points below the horizontal plane of the burners 30. 'Ihe matte line of the furnace is indicated at 52 and the extreme top slag line at 54.

50 In operating the furnace shown, the hot combustion gases for smelting are supplied by the row of burners 30 to the zone l2 and thence from the furnace through up-take 24 to waste heat boilers not shown. Charge is supplied to 5 the bath in the smelting zone by feeders 50 and,

as the operation progresses, there is movement of the liquid matte and slag to the settling Zone I4 in countercurrent flow to the flame and combustion gases delivered by burners 3G. However, not all of the slag is allowed to enter the settling 5 zone as the tapping of slag and matte from that Zone is vso regulated that the top slag line in the furnace is at all times'maintained a sufficient distance above the top of the passageways I3 in wall I Il that unfused charge in the top por- 4tion of the slag is excluded from the settling zone. `Hence, onlyl the matte and fused slag pass into the zone I4. To insure the matte and slag in the settling Zone being at all times in the proper molten state, heat mayy be supplied by a burner (not shown) through port t4, the gases passinginto the smelting Zone through the passageways I8 in the wall IB..

It will be readily apparent to those skilled in the art that the present invention constitutes a decided improvement and affords new results over prior art proposals embodying countercur rent movement of the combustion gases and the smelted or unsmelted charge. Foremost among the advantages attending the use of the invention are lower metal losses and increased recoveries and these, like many lesser advantages', can

be chiefly attributed to the fact that the charge must remain in the smelting zone until smelted,

at which time it is free to pass into the settling zone of the furnace.

The new process of the invention is, of course, not limited in its use to furnaces whose construction follows the exact details heretofore shown and described for illustrative purposes. Thus, the bridge or dam I0 may take many different forms and shapes including cooling with air or water so long as the top of the communicating passageway between the smelting` and settling Zones is sufficiently below the slag line to prevent the unfused charge in the upper portion of the slag from entering the settling zone.

In the drawings, the furnace is shown equipped with gun feeders for introducing hot calcine charge under the burners and this' practise is preferred by reason of the minimization of dusting action thereby obtained. However, other manners of charging can be successfullyr employed such as, for example, side feeding for wet direct-charge smelting. Also, the settling zone of the furnace may be of the same width as the smelting Zone if desired. Such could readily be the case in a side feed furnace or even in a gun fed one by altering the position ofthe feeders.

What is claimed is:

1. In the process of smelting copper in a reverberatory furnace embodying the principle of movement of the matte and slag from the smelting zone into a settling Zone countercurrently to the flow of combustion gases, that improvement which consists in constantly inhibiting the passage of the upper portion of the slag layer from the smelting zone into the settling Zone.

2. The process for treating copper ore which comprises establishing a smelting zone and a settling zone and smelting the ore in the former Zone, flowing the slag and matte from the smelting Zone toward the settling zone in countercurrent to the flow of combustion gases in the smeltmatte and slag flowing into'said settling zone.

RICHARD A. WAGSTAFF.

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