Process for recovering copper from molten converter-type slags or other highly oxidized copper smelter slags containing 7-30 percent by weight of magnetite (Fe.sub.3 O.sub.4). The magnetite in the slag is reduced with carbonaceous materials or other solid reductants. While the slag is mixed with a water cooled, metal-bladed mechanical stirrer, the reductant is reacted with the slag. As a result of stirring the reductant into the slag, the rate of magnetite reduction is highly accelerated. With t...

A directional control valve of a hydraulic pressure control system for an automatic transmission includes a housing, a valve spool, and a compression spring, whereby the housing has five ports. This directional control valve operates such that during the second-third up-shift the pressure of a front clutch and a servo brake release pushes the valve spool in FIG. 1 to the left side so that the port for oil supply to the end clutch opens. Accordingly, the hydraulic pressure is supplied to the end ...

Electronic and hydraulic control system of an automatic transmission for automotive vehicle and method for controlling hydraulic pressure whereby line hydraulic pressure can be compensated. A hydraulic pressure state within the electronic and hydraulic control system is precisely detected and the signal of this detected hydraulic pressure is transmitted to a transmission control unit such that the malfunction of the valves and the correct gear shifting stage can be determined. Since the hydrauli...

A method of driving a CD-ROM drive is provided which includes the steps of setting an initial driving speed of a disk to a predetermined N.times. speed, and measuring a length of time t required for generating a correction error signal (CES) of a digital signal processor (DSP) while playing the disk at the predetermined N.times. speed. If it is determined that the measured CES generation time t is smaller than a first reference time t.sub.1, then the disk is played at N.times. speed. If it is de...

Disclosed is a method for manufacturing a semiconductor device. A multilevel interconnection process for forming a via hole on the first layer electrode and then forming the second layer electrode, comprises the steps of forming the first dielectric layer on the whole surface of the semiconductor substrate where the first layer electrode has been formed, filling the re-entrant by forming the insulating material on the first dielectric layer, laminating a second dielectric layer on the first diel...

A method for divisionally utilizing a memory area may include the steps of setting an input buffer area in the memory, receiving data from a computer, determining whether a user defined character is received, storing data to the input buffer if the user defined character is not received in the above step, determining if a down load flag is set to "0" if the user defined character is received, resetting the memory for the input buffer and down load buffer if the down load flag is set to "0" in th...

Electronic and hydraulic control system of an automatic transmission for automotive vehicle and method for controlling hydraulic pressure whereby line hydraulic pressure can be compensated. A hydraulic pressure state within the electronic and hydraulic control system is precisely detected and the signal of this detected hydraulic pressure is transmitted to a transmission control unit such that the malfunction of the valves and the correct gear shifting stage can be determined. Since the hydrauli...

A test board for testing a semiconductor IC device has a plurality of device attachment pads which are to be electrically connected to a plurality of I/O pins of the semiconductor IC device, a plurality of land pads which are to be electrically connected to a plurality of probe pins of a testing apparatus, a plurality of signal wires electrically connecting the device attachment pads to the land pads, and a plurality of power supply wiring patterns for supplying power to the semiconductor IC dev...

Disclosed is a method for forming multi-layer interconnection of semiconductor device, which allows a contact hole to be formed at a size smaller than a resolution limit of the exposing system. The method comprises the steps of: providing a semiconductor substrate on which a first interconnection layer is formed; forming a first interlayer insulating film on the first interconnection layer and the semiconductor substrate; forming a patterned etch stopper layer on the first interlayer insulating ...

A photoresist discharge monitoring apparatus in which the photoresist discharge rate is monitored by a discharge pump, and based on this monitoring, the discharge pump is controlled, so that a constant photoresist discharge rate is ensured to prevent any occurrence of process defects due to the discharge pump. If the photoresist discharge rate is decreased due to the exhaustion of the life expectancy of the chemical filter, a filter replacement necessity is displayed. That is, a PR (photoresist)...